diff --git a/src/Achievements/Achievements.ts b/src/Achievements/Achievements.ts
index 81c535eb3..b32a6e1f2 100644
--- a/src/Achievements/Achievements.ts
+++ b/src/Achievements/Achievements.ts
@@ -66,11 +66,11 @@ function bitNodeFinishedState(): boolean {
 }
 
 function hasAccessToSF(player: PlayerObject, bn: number): boolean {
-  return player.bitNodeN === bn || player.sourceFiles.some((a) => a.n === bn);
+  return player.bitNodeN === bn || player.sourceFileLvl(bn) > 0;
 }
 
 function knowsAboutBitverse(player: PlayerObject): boolean {
-  return player.sourceFiles.some((a) => a.n === 1);
+  return player.sourceFiles.size > 0;
 }
 
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -274,7 +274,7 @@ export const achievements: Record<string, Achievement> = {
   NS2: {
     ...achievementData["NS2"],
     Icon: "ns2",
-    Condition: () => Player.getHomeComputer().scripts.some((s) => s.filename.endsWith(".js")),
+    Condition: () => [...Player.getHomeComputer().scripts.values()].some((s) => s.filename.endsWith(".js")),
   },
   FROZE: {
     ...achievementData["FROZE"],
@@ -317,7 +317,7 @@ export const achievements: Record<string, Achievement> = {
   SCRIPTS_30: {
     ...achievementData["SCRIPTS_30"],
     Icon: "folders",
-    Condition: () => Player.getHomeComputer().scripts.length >= 30,
+    Condition: () => Player.getHomeComputer().scripts.size >= 30,
   },
   KARMA_1000000: {
     ...achievementData["KARMA_1000000"],
@@ -342,7 +342,7 @@ export const achievements: Record<string, Achievement> = {
   SCRIPT_32GB: {
     ...achievementData["SCRIPT_32GB"],
     Icon: "bigcost",
-    Condition: () => Player.getHomeComputer().scripts.some((s) => (s.ramUsage ?? 0) >= 32),
+    Condition: () => [...Player.getHomeComputer().scripts.values()].some((s) => (s.ramUsage ?? 0) >= 32),
   },
   FIRST_HACKNET_NODE: {
     ...achievementData["FIRST_HACKNET_NODE"],
diff --git a/src/Augmentation/ui/OwnedSourceFiles.tsx b/src/Augmentation/ui/OwnedSourceFiles.tsx
deleted file mode 100644
index 54d434f20..000000000
--- a/src/Augmentation/ui/OwnedSourceFiles.tsx
+++ /dev/null
@@ -1,37 +0,0 @@
-/**
- * React Component for displaying a list of the player's Source-Files
- * on the Augmentations UI
- */
-import * as React from "react";
-
-import { Player } from "@player";
-import { Settings } from "../../Settings/Settings";
-import { OwnedAugmentationsOrderSetting } from "../../Settings/SettingEnums";
-import { SourceFiles } from "../../SourceFile/SourceFiles";
-
-import { SourceFileAccordion } from "../../ui/React/SourceFileAccordion";
-
-export function OwnedSourceFiles(): React.ReactElement {
-  const sourceSfs = Player.sourceFiles.slice();
-
-  if (Settings.OwnedAugmentationsOrder === OwnedAugmentationsOrderSetting.Alphabetically) {
-    sourceSfs.sort((sf1, sf2) => {
-      return sf1.n - sf2.n;
-    });
-  }
-
-  return (
-    <>
-      {sourceSfs.map((e) => {
-        const srcFileKey = "SourceFile" + e.n;
-        const sfObj = SourceFiles[srcFileKey];
-        if (sfObj == null) {
-          console.error(`Invalid source file number: ${e.n}`);
-          return null;
-        }
-
-        return <SourceFileAccordion key={e.n} level={e.lvl} sf={sfObj} />;
-      })}
-    </>
-  );
-}
diff --git a/src/Augmentation/ui/SourceFiles.tsx b/src/Augmentation/ui/SourceFiles.tsx
index e969b46b2..a791918cc 100644
--- a/src/Augmentation/ui/SourceFiles.tsx
+++ b/src/Augmentation/ui/SourceFiles.tsx
@@ -71,27 +71,24 @@ const getMaxLevel = (sfObj: SourceFile | SfMinus1): string | number => {
 };
 
 export function SourceFilesElement(): React.ReactElement {
-  const sourceSfs = Player.sourceFiles.slice();
+  const sourceFilesCopy = new Map(Player.sourceFiles);
   const exploits = Player.exploits;
   // Create a fake SF for -1, if "owned"
   if (exploits.length > 0) {
-    sourceSfs.unshift({
-      n: -1,
-      lvl: exploits.length,
-    });
+    sourceFilesCopy.set(-1, exploits.length);
   }
 
+  const sfList = [...sourceFilesCopy];
   if (Settings.OwnedAugmentationsOrder === OwnedAugmentationsOrderSetting.Alphabetically) {
-    sourceSfs.sort((sf1, sf2) => {
-      return sf1.n - sf2.n;
-    });
+    sfList.sort(([n1, __lvl1], [n2, __lvl2]) => n1 - n2);
   }
 
-  if (sourceSfs.length === 0) {
+  if (sfList.length === 0) {
     return <></>;
   }
 
-  const [selectedSf, setSelectedSf] = useState(sourceSfs[0]);
+  const firstEle = sfList[0];
+  const [selectedSf, setSelectedSf] = useState({ n: firstEle[0], lvl: firstEle[1] });
 
   return (
     <Box sx={{ width: "100%", mt: 1 }}>
@@ -104,8 +101,8 @@ export function SourceFilesElement(): React.ReactElement {
             sx={{ height: 400, overflowY: "scroll", borderRight: `1px solid ${Settings.theme.welllight}` }}
             disablePadding
           >
-            {sourceSfs.map((e, i) => {
-              const sfObj = safeGetSf(e.n);
+            {sfList.map(([n, lvl], i) => {
+              const sfObj = safeGetSf(n);
               if (!sfObj) return;
 
               const maxLevel = getMaxLevel(sfObj);
@@ -113,8 +110,8 @@ export function SourceFilesElement(): React.ReactElement {
               return (
                 <ListItemButton
                   key={i + 1}
-                  onClick={() => setSelectedSf(e)}
-                  selected={selectedSf.n === e.n}
+                  onClick={() => setSelectedSf({ n, lvl })}
+                  selected={selectedSf.n === n}
                   sx={{ py: 0 }}
                 >
                   <ListItemText
@@ -122,7 +119,7 @@ export function SourceFilesElement(): React.ReactElement {
                     primary={<Typography>{sfObj.name}</Typography>}
                     secondary={
                       <Typography>
-                        Level {e.lvl} / {maxLevel}
+                        Level {lvl} / {maxLevel}
                       </Typography>
                     }
                   />
diff --git a/src/DevMenu/ui/SourceFiles.tsx b/src/DevMenu/ui/SourceFiles.tsx
index ac8dfb3d2..c3e5bc7f8 100644
--- a/src/DevMenu/ui/SourceFiles.tsx
+++ b/src/DevMenu/ui/SourceFiles.tsx
@@ -7,7 +7,6 @@ import ExpandMoreIcon from "@mui/icons-material/ExpandMore";
 
 import Typography from "@mui/material/Typography";
 import Button from "@mui/material/Button";
-import { PlayerOwnedSourceFile } from "../../SourceFile/PlayerOwnedSourceFile";
 import { Player } from "@player";
 import ButtonGroup from "@mui/material/ButtonGroup";
 
@@ -21,20 +20,10 @@ export function SourceFiles(): React.ReactElement {
         Player.hacknetNodes = [];
       }
       if (sfLvl === 0) {
-        Player.sourceFiles = Player.sourceFiles.filter((sf) => sf.n !== sfN);
+        Player.sourceFiles.delete(sfN);
         return;
       }
-
-      if (!Player.sourceFiles.some((sf) => sf.n === sfN)) {
-        Player.sourceFiles.push(new PlayerOwnedSourceFile(sfN, sfLvl));
-        return;
-      }
-
-      for (let i = 0; i < Player.sourceFiles.length; i++) {
-        if (Player.sourceFiles[i].n === sfN) {
-          Player.sourceFiles[i].lvl = sfLvl;
-        }
-      }
+      Player.sourceFiles.set(sfN, sfLvl);
     };
   }
 
diff --git a/src/Diagnostic/FileDiagnosticModal.tsx b/src/Diagnostic/FileDiagnosticModal.tsx
index 02c0a9696..d21cab4cb 100644
--- a/src/Diagnostic/FileDiagnosticModal.tsx
+++ b/src/Diagnostic/FileDiagnosticModal.tsx
@@ -15,16 +15,17 @@ import Accordion from "@mui/material/Accordion";
 import AccordionSummary from "@mui/material/AccordionSummary";
 import AccordionDetails from "@mui/material/AccordionDetails";
 import ExpandMoreIcon from "@mui/icons-material/ExpandMore";
+import { ServerName } from "../Types/strings";
 
 interface IServerProps {
-  hostname: string;
+  hostname: ServerName;
 }
 
 function ServerAccordion(props: IServerProps): React.ReactElement {
   const server = GetServer(props.hostname);
   if (server === null) throw new Error(`server '${props.hostname}' should not be null`);
   let totalSize = 0;
-  for (const f of server.scripts) {
+  for (const f of server.scripts.values()) {
     totalSize += f.code.length;
   }
 
@@ -43,7 +44,7 @@ function ServerAccordion(props: IServerProps): React.ReactElement {
 
   const files: File[] = [];
 
-  for (const f of server.scripts) {
+  for (const f of server.scripts.values()) {
     files.push({ name: f.filename, size: f.code.length });
   }
 
diff --git a/src/Electron.tsx b/src/Electron.tsx
index d919bb4f9..055e395aa 100644
--- a/src/Electron.tsx
+++ b/src/Electron.tsx
@@ -75,7 +75,7 @@ function initWebserver(): void {
     return {
       res: true,
       data: {
-        files: home.scripts.map((script) => ({
+        files: [...home.scripts.values()].map((script) => ({
           filename: script.filename,
           code: script.code,
           ramUsage: script.ramUsage,
diff --git a/src/Locations/ui/SpecialLocation.tsx b/src/Locations/ui/SpecialLocation.tsx
index dd358e2e8..ebf9d0b86 100644
--- a/src/Locations/ui/SpecialLocation.tsx
+++ b/src/Locations/ui/SpecialLocation.tsx
@@ -93,7 +93,7 @@ export function SpecialLocation(props: IProps): React.ReactElement {
     function EatNoodles(): void {
       SnackbarEvents.emit("You ate some delicious noodles and feel refreshed", ToastVariant.SUCCESS, 2000);
       N00dles(); // This is the true power of the noodles.
-      if (Player.sourceFiles.length > 0) Player.giveExploit(Exploit.N00dles);
+      if (Player.sourceFiles.size > 0) Player.giveExploit(Exploit.N00dles);
       if (Player.sourceFileLvl(5) > 0 || Player.bitNodeN === 5) {
         Player.exp.intelligence *= 1.0000000000000002;
       }
diff --git a/src/Message/MessageHelpers.tsx b/src/Message/MessageHelpers.tsx
index d70defb95..4f854575d 100644
--- a/src/Message/MessageHelpers.tsx
+++ b/src/Message/MessageHelpers.tsx
@@ -80,7 +80,7 @@ function checkForMessagesToSend(): void {
     }
     //If the daemon can be hacked, send the player icarus.msg
     if (Player.skills.hacking >= worldDaemon.requiredHackingSkill) {
-      sendMessage(redpill, Player.sourceFiles.length === 0);
+      sendMessage(redpill, Player.sourceFiles.size === 0);
     }
     //If the daemon cannot be hacked, send the player truthgazer.msg a single time.
     else if (!recvd(truthGazer)) {
diff --git a/src/Netscript/WorkerScript.ts b/src/Netscript/WorkerScript.ts
index 24cf51eb3..e9613a58d 100644
--- a/src/Netscript/WorkerScript.ts
+++ b/src/Netscript/WorkerScript.ts
@@ -96,16 +96,11 @@ export class WorkerScript {
     if (server == null) {
       throw new Error(`WorkerScript constructed with invalid server ip: ${this.hostname}`);
     }
-    let found = false;
-    for (let i = 0; i < server.scripts.length; ++i) {
-      if (server.scripts[i].filename === this.name) {
-        found = true;
-        this.code = server.scripts[i].code;
-      }
-    }
-    if (!found) {
+    const script = server.scripts.get(this.name);
+    if (!script) {
       throw new Error(`WorkerScript constructed with invalid script filename: ${this.name}`);
     }
+    this.code = script.code;
     this.scriptRef = runningScriptObj;
     this.args = runningScriptObj.args.slice();
     this.env = new Environment();
@@ -127,16 +122,14 @@ export class WorkerScript {
    */
   getScript(): Script | null {
     const server = this.getServer();
-    for (let i = 0; i < server.scripts.length; ++i) {
-      if (server.scripts[i].filename === this.name) {
-        return server.scripts[i];
-      }
+    const script = server.scripts.get(this.name);
+    if (!script) {
+      console.error(
+        "Failed to find underlying Script object in WorkerScript.getScript(). This probably means somethings wrong",
+      );
+      return null;
     }
-
-    console.error(
-      "Failed to find underlying Script object in WorkerScript.getScript(). This probably means somethings wrong",
-    );
-    return null;
+    return script;
   }
 
   /**
@@ -144,17 +137,7 @@ export class WorkerScript {
    * or null if it cannot be found
    */
   getScriptOnServer(fn: string, server: BaseServer): Script | null {
-    if (server == null) {
-      server = this.getServer();
-    }
-
-    for (let i = 0; i < server.scripts.length; ++i) {
-      if (server.scripts[i].filename === fn) {
-        return server.scripts[i];
-      }
-    }
-
-    return null;
+    return server.scripts.get(fn) ?? null;
   }
 
   shouldLog(fn: string): boolean {
diff --git a/src/NetscriptFunctions.ts b/src/NetscriptFunctions.ts
index 50b4a5fc0..4b81a34ba 100644
--- a/src/NetscriptFunctions.ts
+++ b/src/NetscriptFunctions.ts
@@ -36,7 +36,7 @@ import {
 } from "./Server/ServerPurchases";
 import { Server } from "./Server/Server";
 import { influenceStockThroughServerGrow } from "./StockMarket/PlayerInfluencing";
-import { areFilesEqual, isValidFilePath, removeLeadingSlash } from "./Terminal/DirectoryHelpers";
+import { isValidFilePath, removeLeadingSlash } from "./Terminal/DirectoryHelpers";
 import { TextFile, getTextFile, createTextFile } from "./TextFile";
 import { runScriptFromScript } from "./NetscriptWorker";
 import { killWorkerScript } from "./Netscript/killWorkerScript";
@@ -877,7 +877,7 @@ export const ns: InternalAPI<NSFull> = {
         }
 
         // Scp for script files
-        const sourceScript = sourceServ.scripts.find((script) => script.filename === file);
+        const sourceScript = sourceServ.scripts.get(file);
         if (!sourceScript) {
           helpers.log(ctx, () => `File '${file}' does not exist.`);
           noFailures = false;
@@ -885,7 +885,7 @@ export const ns: InternalAPI<NSFull> = {
         }
 
         // Overwrite script if it already exists
-        const destScript = destServer.scripts.find((script) => script.filename === file);
+        const destScript = destServer.scripts.get(file);
         if (destScript) {
           if (destScript.code === sourceScript.code) {
             helpers.log(ctx, () => `Identical file '${file}' was already on '${destServer?.hostname}'`);
@@ -900,7 +900,7 @@ export const ns: InternalAPI<NSFull> = {
 
         // Create new script if it does not already exist
         const newScript = new Script(file, sourceScript.code, destServer.hostname);
-        destServer.scripts.push(newScript);
+        destServer.scripts.set(file, newScript);
         helpers.log(ctx, () => `File '${file}' copied over to '${destServer?.hostname}'.`);
       }
 
@@ -915,7 +915,7 @@ export const ns: InternalAPI<NSFull> = {
       ...server.contracts.map((contract) => contract.fn),
       ...server.messages,
       ...server.programs,
-      ...server.scripts.map((script) => script.filename),
+      ...server.scripts.keys(),
       ...server.textFiles.map((textFile) => textFile.filename),
     ];
 
@@ -1147,11 +1147,7 @@ export const ns: InternalAPI<NSFull> = {
       const filename = helpers.string(ctx, "filename", _filename);
       const hostname = helpers.string(ctx, "hostname", _hostname);
       const server = helpers.getServer(ctx, hostname);
-      for (let i = 0; i < server.scripts.length; ++i) {
-        if (filename == server.scripts[i].filename) {
-          return true;
-        }
-      }
+      if (server.scripts.has(filename)) return true;
       for (let i = 0; i < server.programs.length; ++i) {
         if (filename.toLowerCase() == server.programs[i].toLowerCase()) {
           return true;
@@ -1366,47 +1362,45 @@ export const ns: InternalAPI<NSFull> = {
     }
     return writePort(portNumber, data);
   },
-  write:
-    (ctx) =>
-    (_filename, _data = "", _mode = "a") => {
-      let fn = helpers.string(ctx, "handle", _filename);
-      const data = helpers.string(ctx, "data", _data);
-      const mode = helpers.string(ctx, "mode", _mode);
-      if (!isValidFilePath(fn)) throw helpers.makeRuntimeErrorMsg(ctx, `Invalid filepath: ${fn}`);
+  write: (ctx) => (_filename, _data, _mode) => {
+    let filename = helpers.string(ctx, "handle", _filename);
+    const data = helpers.string(ctx, "data", _data ?? "");
+    const mode = helpers.string(ctx, "mode", _mode ?? "a");
+    if (!isValidFilePath(filename)) throw helpers.makeRuntimeErrorMsg(ctx, `Invalid filepath: ${filename}`);
 
-      if (fn.lastIndexOf("/") === 0) fn = removeLeadingSlash(fn);
+    if (filename.lastIndexOf("/") === 0) filename = removeLeadingSlash(filename);
 
-      const server = helpers.getServer(ctx, ctx.workerScript.hostname);
+    const server = helpers.getServer(ctx, ctx.workerScript.hostname);
 
-      if (isScriptFilename(fn)) {
-        // Write to script
-        let script = ctx.workerScript.getScriptOnServer(fn, server);
-        if (script == null) {
-          // Create a new script
-          script = new Script(fn, String(data), server.hostname);
-          server.scripts.push(script);
-          return;
-        }
-        mode === "w" ? (script.code = String(data)) : (script.code += data);
-        // Set ram to null so a recalc is performed the next time ram usage is needed
-        script.invalidateModule();
+    if (isScriptFilename(filename)) {
+      // Write to script
+      let script = ctx.workerScript.getScriptOnServer(filename, server);
+      if (!script) {
+        // Create a new script
+        script = new Script(filename, String(data), server.hostname);
+        server.scripts.set(filename, script);
         return;
-      } else {
-        // Write to text file
-        if (!fn.endsWith(".txt")) throw helpers.makeRuntimeErrorMsg(ctx, `Invalid filename: ${fn}`);
-        const txtFile = getTextFile(fn, server);
-        if (txtFile == null) {
-          createTextFile(fn, String(data), server);
-          return;
-        }
-        if (mode === "w") {
-          txtFile.write(String(data));
-        } else {
-          txtFile.append(String(data));
-        }
       }
+      mode === "w" ? (script.code = data) : (script.code += data);
+      // Set ram to null so a recalc is performed the next time ram usage is needed
+      script.invalidateModule();
       return;
-    },
+    } else {
+      // Write to text file
+      if (!filename.endsWith(".txt")) throw helpers.makeRuntimeErrorMsg(ctx, `Invalid filename: ${filename}`);
+      const txtFile = getTextFile(filename, server);
+      if (txtFile == null) {
+        createTextFile(filename, String(data), server);
+        return;
+      }
+      if (mode === "w") {
+        txtFile.write(String(data));
+      } else {
+        txtFile.append(String(data));
+      }
+    }
+    return;
+  },
   tryWritePort: (ctx) => (_portNumber, data) => {
     const portNumber = helpers.portNumber(ctx, _portNumber);
     if (typeof data !== "string" && typeof data !== "number") {
@@ -1515,21 +1509,19 @@ export const ns: InternalAPI<NSFull> = {
   getScriptName: (ctx) => () => {
     return ctx.workerScript.name;
   },
-  getScriptRam:
-    (ctx) =>
-    (_scriptname, _hostname = ctx.workerScript.hostname) => {
-      const scriptname = helpers.string(ctx, "scriptname", _scriptname);
-      const hostname = helpers.string(ctx, "hostname", _hostname);
-      const server = helpers.getServer(ctx, hostname);
-      const script = server.scripts.find((serverScript) => areFilesEqual(serverScript.filename, scriptname));
-      if (!script) return 0;
-      const ramUsage = script.getRamUsage(server.scripts);
-      if (!ramUsage) {
-        helpers.log(ctx, () => `Could not calculate ram usage for ${scriptname} on ${hostname}.`);
-        return 0;
-      }
-      return ramUsage;
-    },
+  getScriptRam: (ctx) => (_scriptname, _hostname) => {
+    const scriptname = helpers.string(ctx, "scriptname", _scriptname);
+    const hostname = helpers.string(ctx, "hostname", _hostname ?? ctx.workerScript.hostname);
+    const server = helpers.getServer(ctx, hostname);
+    const script = server.scripts.get(scriptname);
+    if (!script) return 0;
+    const ramUsage = script.getRamUsage(server.scripts);
+    if (!ramUsage) {
+      helpers.log(ctx, () => `Could not calculate ram usage for ${scriptname} on ${hostname}.`);
+      return 0;
+    }
+    return ramUsage;
+  },
   getRunningScript:
     (ctx) =>
     (fn, hostname, ...args) => {
@@ -1781,7 +1773,7 @@ export const ns: InternalAPI<NSFull> = {
     }; // Wrap the user function to prevent WorkerScript leaking as 'this'
   },
   mv: (ctx) => (_host, _source, _destination) => {
-    const host = helpers.string(ctx, "host", _host);
+    const hostname = helpers.string(ctx, "host", _host);
     const source = helpers.string(ctx, "source", _source);
     const destination = helpers.string(ctx, "destination", _destination);
 
@@ -1800,44 +1792,40 @@ export const ns: InternalAPI<NSFull> = {
       return;
     }
 
-    const destServer = helpers.getServer(ctx, host);
+    const server = helpers.getServer(ctx, hostname);
 
-    if (!source_is_txt && destServer.isRunning(source))
+    if (!source_is_txt && server.isRunning(source))
       throw helpers.makeRuntimeErrorMsg(ctx, `Cannot use 'mv' on a script that is running`);
 
     interface File {
       filename: string;
     }
+    let source_file: File | undefined;
+    let dest_file: File | undefined;
 
-    const files = source_is_txt ? destServer.textFiles : destServer.scripts;
-    let source_file: File | null = null;
-    let dest_file: File | null = null;
-
-    for (let i = 0; i < files.length; ++i) {
-      const file = files[i];
-      if (file.filename === source) {
-        source_file = file;
-      } else if (file.filename === destination) {
-        dest_file = file;
-      }
+    if (source_is_txt) {
+      // Traverses twice potentially. Inefficient but will soon be replaced with a map.
+      source_file = server.textFiles.find((textFile) => textFile.filename === source);
+      dest_file = server.textFiles.find((textFile) => textFile.filename === destination);
+    } else {
+      source_file = server.scripts.get(source);
+      dest_file = server.scripts.get(destination);
     }
+    if (!source_file) throw helpers.makeRuntimeErrorMsg(ctx, `Source file ${source} does not exist`);
 
-    if (source_file == null) throw helpers.makeRuntimeErrorMsg(ctx, `Source file ${source} does not exist`);
-
-    if (dest_file != null) {
+    if (dest_file) {
       if (dest_file instanceof TextFile && source_file instanceof TextFile) {
         dest_file.text = source_file.text;
       } else if (dest_file instanceof Script && source_file instanceof Script) {
         dest_file.code = source_file.code;
+        // Source needs to be invalidated as well, to invalidate its dependents
+        source_file.invalidateModule();
         dest_file.invalidateModule();
       }
-
-      destServer.removeFile(source);
+      server.removeFile(source);
     } else {
       source_file.filename = destination;
-      if (source_file instanceof Script) {
-        source_file.invalidateModule();
-      }
+      if (source_file instanceof Script) source_file.invalidateModule();
     }
   },
   flags: Flags,
diff --git a/src/NetscriptFunctions/Bladeburner.ts b/src/NetscriptFunctions/Bladeburner.ts
index 2a4c8925d..3c043e9b1 100644
--- a/src/NetscriptFunctions/Bladeburner.ts
+++ b/src/NetscriptFunctions/Bladeburner.ts
@@ -15,7 +15,7 @@ export function NetscriptBladeburner(): InternalAPI<INetscriptBladeburner> {
     return;
   };
   const getBladeburner = function (ctx: NetscriptContext): Bladeburner {
-    const apiAccess = Player.bitNodeN === 7 || Player.sourceFiles.some((a) => a.n === 7);
+    const apiAccess = Player.bitNodeN === 7 || Player.sourceFileLvl(7) > 0;
     if (!apiAccess) {
       throw helpers.makeRuntimeErrorMsg(ctx, "You have not unlocked the bladeburner API.", "API ACCESS");
     }
diff --git a/src/NetscriptFunctions/Formulas.ts b/src/NetscriptFunctions/Formulas.ts
index dae80bb81..154d44aa5 100644
--- a/src/NetscriptFunctions/Formulas.ts
+++ b/src/NetscriptFunctions/Formulas.ts
@@ -94,7 +94,7 @@ export function NetscriptFormulas(): InternalAPI<IFormulas> {
       numPeopleKilled: 0,
       money: 0,
       city: CityName.Sector12,
-      location: "",
+      location: LocationName.TravelAgency,
       bitNodeN: 0,
       totalPlaytime: 0,
       jobs: {},
diff --git a/src/NetscriptFunctions/Singularity.ts b/src/NetscriptFunctions/Singularity.ts
index c8fd133ca..e775d1735 100644
--- a/src/NetscriptFunctions/Singularity.ts
+++ b/src/NetscriptFunctions/Singularity.ts
@@ -50,7 +50,6 @@ import { canGetBonus, onExport } from "../ExportBonus";
 import { saveObject } from "../SaveObject";
 import { calculateCrimeWorkStats } from "../Work/Formulas";
 import { findEnumMember } from "../utils/helpers/enum";
-import { areFilesEqual } from "../Terminal/DirectoryHelpers";
 import { Engine } from "../engine";
 import { checkEnum } from "../utils/helpers/enum";
 
@@ -81,7 +80,7 @@ export function NetscriptSingularity(): InternalAPI<ISingularity> {
     //Run a script after reset
     if (!cbScript) return;
     const home = Player.getHomeComputer();
-    const script = home.scripts.find((serverScript) => areFilesEqual(serverScript.filename, cbScript));
+    const script = home.scripts.get(cbScript);
     if (!script) return;
     const ramUsage = script.getRamUsage(home.scripts);
     if (!ramUsage) {
@@ -110,9 +109,7 @@ export function NetscriptSingularity(): InternalAPI<ISingularity> {
       return res;
     },
     getOwnedSourceFiles: () => () => {
-      return Player.sourceFiles.map((sf) => {
-        return { n: sf.n, lvl: sf.lvl };
-      });
+      return [...Player.sourceFiles].map(([n, lvl]) => ({ n, lvl }));
     },
     getAugmentationsFromFaction: (ctx) => (_facName) => {
       helpers.checkSingularityAccess(ctx);
diff --git a/src/NetscriptJSEvaluator.ts b/src/NetscriptJSEvaluator.ts
index 3660d96b6..bd1e78bd8 100644
--- a/src/NetscriptJSEvaluator.ts
+++ b/src/NetscriptJSEvaluator.ts
@@ -7,7 +7,8 @@ import { parse } from "acorn";
 
 import { LoadedModule, ScriptURL, ScriptModule } from "./Script/LoadedModule";
 import { Script } from "./Script/Script";
-import { areImportsEquals, removeLeadingSlash } from "./Terminal/DirectoryHelpers";
+import { removeLeadingSlash } from "./Terminal/DirectoryHelpers";
+import { ScriptFilename, scriptFilenameFromImport } from "./Types/strings";
 
 // Acorn type def is straight up incomplete so we have to fill with our own.
 export type Node = any;
@@ -46,7 +47,7 @@ const cleanup = new FinalizationRegistry((mapKey: string) => {
   }
 });
 
-export function compile(script: Script, scripts: Script[]): Promise<ScriptModule> {
+export function compile(script: Script, scripts: Map<ScriptFilename, Script>): Promise<ScriptModule> {
   // Return the module if it already exists
   if (script.mod) return script.mod.module;
 
@@ -75,7 +76,7 @@ function addDependencyInfo(script: Script, seenStack: Script[]) {
  * @param scripts array of other scripts on the server
  * @param seenStack A stack of scripts that were higher up in the import tree in a recursive call.
  */
-function generateLoadedModule(script: Script, scripts: Script[], seenStack: Script[]): LoadedModule {
+function generateLoadedModule(script: Script, scripts: Map<ScriptFilename, Script>, seenStack: Script[]): LoadedModule {
   // Early return for recursive calls where the script already has a URL
   if (script.mod) {
     addDependencyInfo(script, seenStack);
@@ -124,10 +125,10 @@ function generateLoadedModule(script: Script, scripts: Script[], seenStack: Scri
   let newCode = script.code;
   // Loop through each node and replace the script name with a blob url.
   for (const node of importNodes) {
-    const filename = node.filename.startsWith("./") ? node.filename.substring(2) : node.filename;
+    const filename = scriptFilenameFromImport(node.filename);
 
     // Find the corresponding script.
-    const importedScript = scripts.find((s) => areImportsEquals(s.filename, filename));
+    const importedScript = scripts.get(filename);
     if (!importedScript) continue;
 
     seenStack.push(script);
diff --git a/src/NetscriptWorker.ts b/src/NetscriptWorker.ts
index 68b8e1d86..dde2c2396 100644
--- a/src/NetscriptWorker.ts
+++ b/src/NetscriptWorker.ts
@@ -29,10 +29,10 @@ import { roundToTwo } from "./utils/helpers/roundToTwo";
 
 import { parse } from "acorn";
 import { simple as walksimple } from "acorn-walk";
-import { areFilesEqual } from "./Terminal/DirectoryHelpers";
 import { Terminal } from "./Terminal";
 import { ScriptArg } from "@nsdefs";
 import { handleUnknownError, CompleteRunOptions } from "./Netscript/NetscriptHelpers";
+import { scriptFilenameFromImport } from "./Types/strings";
 
 export const NetscriptPorts: Map<PortNumber, Port> = new Map();
 
@@ -147,12 +147,7 @@ function processNetscript1Imports(code: string, workerScript: WorkerScript): { c
   }
 
   function getScript(scriptName: string): Script | null {
-    for (let i = 0; i < server.scripts.length; ++i) {
-      if (server.scripts[i].filename === scriptName) {
-        return server.scripts[i];
-      }
-    }
-    return null;
+    return server.scripts.get(scriptName) ?? null;
   }
 
   let generatedCode = ""; // Generated Javascript Code
@@ -162,10 +157,7 @@ function processNetscript1Imports(code: string, workerScript: WorkerScript): { c
   walksimple(ast, {
     ImportDeclaration: (node: Node) => {
       hasImports = true;
-      let scriptName = node.source.value;
-      if (scriptName.startsWith("./")) {
-        scriptName = scriptName.slice(2);
-      }
+      const scriptName = scriptFilenameFromImport(node.source.value, true);
       const script = getScript(scriptName);
       if (script == null) {
         throw new Error("'Import' failed due to invalid script: " + scriptName);
@@ -398,7 +390,7 @@ export function runScriptFromScript(
    * running a large number of scripts. */
 
   // Find the script, fail if it doesn't exist.
-  const script = host.scripts.find((serverScript) => areFilesEqual(serverScript.filename, scriptname));
+  const script = host.scripts.get(scriptname);
   if (!script) {
     workerScript.log(caller, () => `Could not find script '${scriptname}' on '${host.hostname}'`);
     return 0;
diff --git a/src/PersonObjects/Player/PlayerObject.ts b/src/PersonObjects/Player/PlayerObject.ts
index 6385572b1..18cb5048e 100644
--- a/src/PersonObjects/Player/PlayerObject.ts
+++ b/src/PersonObjects/Player/PlayerObject.ts
@@ -8,7 +8,6 @@ import * as workMethods from "./PlayerObjectWorkMethods";
 
 import { setPlayer } from "../../Player";
 import { Sleeve } from "../Sleeve/Sleeve";
-import { PlayerOwnedSourceFile } from "../../SourceFile/PlayerOwnedSourceFile";
 import { Exploit } from "../../Exploits/Exploit";
 
 import { LocationName } from "../../Enums";
@@ -21,6 +20,7 @@ import { HashManager } from "../../Hacknet/HashManager";
 
 import { MoneySourceTracker } from "../../utils/MoneySourceTracker";
 import { constructorsForReviver, Generic_toJSON, Generic_fromJSON, IReviverValue } from "../../utils/JSONReviver";
+import { JSONMap } from "../../Types/Jsonable";
 import { PlayerAchievement } from "../../Achievements/Achievements";
 import { cyrb53 } from "../../utils/StringHelperFunctions";
 import { getRandomInt } from "../../utils/helpers/getRandomInt";
@@ -59,7 +59,7 @@ export class PlayerObject extends Person implements IPlayer {
   scriptProdSinceLastAug = 0;
   sleeves: Sleeve[] = [];
   sleevesFromCovenant = 0;
-  sourceFiles: PlayerOwnedSourceFile[] = [];
+  sourceFiles: JSONMap<number, number> = new JSONMap();
   exploits: Exploit[] = [];
   achievements: PlayerAchievement[] = [];
   terminalCommandHistory: string[] = [];
@@ -168,9 +168,15 @@ export class PlayerObject extends Person implements IPlayer {
 
   /** Initializes a PlayerObject object from a JSON save state. */
   static fromJSON(value: IReviverValue): PlayerObject {
-    if (!value.data.hp?.current || !value.data.hp?.max) value.data.hp = { current: 10, max: 10 };
     const player = Generic_fromJSON(PlayerObject, value.data);
-    if (player.money === null) player.money = 0;
+    player.hp = { current: player.hp?.current ?? 10, max: player.hp?.max ?? 10 };
+    player.money ??= 0;
+    player.updateSkillLevels();
+    if (Array.isArray(player.sourceFiles)) {
+      // Expect pre-2.3 sourcefile format here.
+      type OldSourceFiles = { n: number; lvl: number }[];
+      player.sourceFiles = new JSONMap((player.sourceFiles as OldSourceFiles).map(({ n, lvl }) => [n, lvl]));
+    }
     return player;
   }
 }
diff --git a/src/PersonObjects/Player/PlayerObjectGeneralMethods.ts b/src/PersonObjects/Player/PlayerObjectGeneralMethods.ts
index 06af668c8..59fd504c7 100644
--- a/src/PersonObjects/Player/PlayerObjectGeneralMethods.ts
+++ b/src/PersonObjects/Player/PlayerObjectGeneralMethods.ts
@@ -586,14 +586,14 @@ export function reapplyAllSourceFiles(this: PlayerObject): void {
   //Will always be called after reapplyAllAugmentations() so multipliers do not have to be reset
   //this.resetMultipliers();
 
-  for (let i = 0; i < this.sourceFiles.length; ++i) {
-    const srcFileKey = "SourceFile" + this.sourceFiles[i].n;
+  for (const [bn, lvl] of this.sourceFiles) {
+    const srcFileKey = "SourceFile" + bn;
     const sourceFileObject = SourceFiles[srcFileKey];
-    if (sourceFileObject == null) {
-      console.error(`Invalid source file number: ${this.sourceFiles[i].n}`);
+    if (!sourceFileObject) {
+      console.error(`Invalid source file number: ${bn}`);
       continue;
     }
-    applySourceFile(this.sourceFiles[i]);
+    applySourceFile(bn, lvl);
   }
   applyExploit();
   this.updateSkillLevels();
@@ -1222,9 +1222,7 @@ export function canAccessCotMG(this: PlayerObject): boolean {
 }
 
 export function sourceFileLvl(this: PlayerObject, n: number): number {
-  const sf = this.sourceFiles.find((sf) => sf.n === n);
-  if (!sf) return 0;
-  return sf.lvl;
+  return this.sourceFiles.get(n) ?? 0;
 }
 
 export function focusPenalty(this: PlayerObject): number {
diff --git a/src/Player.ts b/src/Player.ts
index 5ede04b58..5d465375d 100644
--- a/src/Player.ts
+++ b/src/Player.ts
@@ -10,8 +10,9 @@ export function setPlayer(playerObj: PlayerObject): void {
   Player = playerObj;
 }
 
-export function loadPlayer(saveString: string): void {
-  Player = JSON.parse(saveString, Reviver);
-  Player.money = parseFloat(Player.money + "");
-  Player.exploits = sanitizeExploits(Player.exploits);
+export function loadPlayer(saveString: string): PlayerObject {
+  const player = JSON.parse(saveString, Reviver);
+  player.money = parseFloat(player.money + "");
+  player.exploits = sanitizeExploits(player.exploits);
+  return player;
 }
diff --git a/src/Prestige.ts b/src/Prestige.ts
index b3728e2f0..16f8e75e1 100755
--- a/src/Prestige.ts
+++ b/src/Prestige.ts
@@ -192,7 +192,7 @@ export function prestigeSourceFile(flume: boolean): void {
   AddToAllServers(homeComp);
   prestigeHomeComputer(homeComp);
   // Ram usage needs to be cleared for bitnode-level resets, due to possible change in singularity cost.
-  for (const script of homeComp.scripts) script.ramUsage = null;
+  for (const script of homeComp.scripts.values()) script.ramUsage = null;
 
   // Re-create foreign servers
   initForeignServers(Player.getHomeComputer());
diff --git a/src/Programs/data/ProgramsMetadata.ts b/src/Programs/data/ProgramsMetadata.ts
index 594befad0..f71921550 100644
--- a/src/Programs/data/ProgramsMetadata.ts
+++ b/src/Programs/data/ProgramsMetadata.ts
@@ -20,7 +20,7 @@ function requireHackingLevel(lvl: number) {
 
 function bitFlumeRequirements() {
   return function () {
-    return Player.sourceFiles.length > 0 && Player.skills.hacking >= 1;
+    return Player.sourceFiles.size > 0 && Player.skills.hacking >= 1;
   };
 }
 
diff --git a/src/RedPill.tsx b/src/RedPill.tsx
index 387c63600..80a7d13be 100644
--- a/src/RedPill.tsx
+++ b/src/RedPill.tsx
@@ -1,7 +1,6 @@
 /** Implementation for what happens when you destroy a BitNode */
 import React from "react";
 import { Player } from "@player";
-import { PlayerOwnedSourceFile } from "./SourceFile/PlayerOwnedSourceFile";
 import { SourceFiles } from "./SourceFile/SourceFiles";
 
 import { dialogBoxCreate } from "./ui/React/DialogBox";
@@ -12,32 +11,26 @@ import { Engine } from "./engine";
 function giveSourceFile(bitNodeNumber: number): void {
   const sourceFileKey = "SourceFile" + bitNodeNumber.toString();
   const sourceFile = SourceFiles[sourceFileKey];
-  if (sourceFile == null) {
+  if (!sourceFile) {
     console.error(`Could not find source file for Bit node: ${bitNodeNumber}`);
     return;
   }
 
   // Check if player already has this source file
-  const ownedSourceFile = Player.sourceFiles.find((sourceFile) => sourceFile.n === bitNodeNumber);
+  let lvl = Player.sourceFileLvl(bitNodeNumber);
 
-  if (ownedSourceFile) {
-    if (ownedSourceFile.lvl >= 3 && ownedSourceFile.n !== 12) {
+  if (lvl > 0) {
+    if (lvl >= 3 && bitNodeNumber !== 12) {
       dialogBoxCreate(
         `The Source-File for the BitNode you just destroyed, ${sourceFile.name}, is already at max level!`,
       );
     } else {
-      ++ownedSourceFile.lvl;
-      dialogBoxCreate(
-        sourceFile.name +
-          " was upgraded to level " +
-          ownedSourceFile.lvl +
-          " for " +
-          "destroying its corresponding BitNode!",
-      );
+      lvl++;
+      Player.sourceFiles.set(bitNodeNumber, lvl);
+      dialogBoxCreate(`${sourceFile.name} was upgraded to level ${lvl} for destroying its corresponding BitNode!`);
     }
   } else {
-    const newSrcFile = new PlayerOwnedSourceFile(bitNodeNumber, 1);
-    Player.sourceFiles.push(newSrcFile);
+    Player.sourceFiles.set(bitNodeNumber, 1);
     if (bitNodeNumber === 5 && Player.skills.intelligence === 0) {
       Player.skills.intelligence = 1;
     }
diff --git a/src/RemoteFileAPI/MessageHandlers.ts b/src/RemoteFileAPI/MessageHandlers.ts
index 39740ec96..30344d5b2 100644
--- a/src/RemoteFileAPI/MessageHandlers.ts
+++ b/src/RemoteFileAPI/MessageHandlers.ts
@@ -87,10 +87,7 @@ export const RFARequestHandler: Record<string, (message: RFAMessage) => void | R
     const server = GetServer(msg.params.server);
     if (!server) return error("Server hostname invalid", msg);
 
-    const fileNameList: string[] = [
-      ...server.textFiles.map((txt): string => txt.filename),
-      ...server.scripts.map((scr): string => scr.filename),
-    ];
+    const fileNameList: string[] = [...server.textFiles.map((txt): string => txt.filename), ...server.scripts.keys()];
 
     return new RFAMessage({ result: fileNameList, id: msg.id });
   },
@@ -105,10 +102,8 @@ export const RFARequestHandler: Record<string, (message: RFAMessage) => void | R
       ...server.textFiles.map((txt): FileContent => {
         return { filename: txt.filename, content: txt.text };
       }),
-      ...server.scripts.map((scr): FileContent => {
-        return { filename: scr.filename, content: scr.code };
-      }),
     ];
+    for (const [filename, script] of server.scripts) fileList.push({ filename, content: script.code });
 
     return new RFAMessage({ result: fileList, id: msg.id });
   },
diff --git a/src/SaveObject.tsx b/src/SaveObject.tsx
index a599161e4..06b95a44a 100755
--- a/src/SaveObject.tsx
+++ b/src/SaveObject.tsx
@@ -3,7 +3,7 @@ import { Companies, loadCompanies } from "./Company/Companies";
 import { CONSTANTS } from "./Constants";
 import { Factions, loadFactions } from "./Faction/Factions";
 import { loadAllGangs, AllGangs } from "./Gang/AllGangs";
-import { Player, loadPlayer } from "./Player";
+import { Player, setPlayer, loadPlayer } from "./Player";
 import {
   saveAllServers,
   loadAllServers,
@@ -27,7 +27,6 @@ import { AwardNFG, v1APIBreak } from "./utils/v1APIBreak";
 import { AugmentationNames } from "./Augmentation/data/AugmentationNames";
 import { PlayerOwnedAugmentation } from "./Augmentation/PlayerOwnedAugmentation";
 import { LocationName } from "./Enums";
-import { PlayerObject } from "./PersonObjects/Player/PlayerObject";
 import { pushGameSaved } from "./Electron";
 import { defaultMonacoTheme } from "./ScriptEditor/ui/themes";
 import { FactionNames } from "./Faction/data/FactionNames";
@@ -35,6 +34,8 @@ import { Faction } from "./Faction/Faction";
 import { safelyCreateUniqueServer } from "./Server/ServerHelpers";
 import { SpecialServers } from "./Server/data/SpecialServers";
 import { v2APIBreak } from "./utils/v2APIBreak";
+import { Script } from "./Script/Script";
+import { JSONMap } from "./Types/Jsonable";
 
 /* SaveObject.js
  *  Defines the object used to save/load games
@@ -208,7 +209,7 @@ class BitburnerSaveObject {
       base64: base64Save,
     };
 
-    const importedPlayer = PlayerObject.fromJSON(JSON.parse(parsedSave.data.PlayerSave));
+    const importedPlayer = loadPlayer(parsedSave.data.PlayerSave);
 
     const playerData: ImportPlayerData = {
       identifier: importedPlayer.identifier,
@@ -224,7 +225,7 @@ class BitburnerSaveObject {
 
       bitNode: importedPlayer.bitNodeN,
       bitNodeLevel: importedPlayer.sourceFileLvl(Player.bitNodeN) + 1,
-      sourceFiles: importedPlayer.sourceFiles?.reduce<number>((total, current) => (total += current.lvl), 0) ?? 0,
+      sourceFiles: [...importedPlayer.sourceFiles].reduce<number>((total, [__bn, lvl]) => (total += lvl), 0),
     };
 
     data.playerData = playerData;
@@ -345,7 +346,7 @@ function evaluateVersionCompatibility(ver: string | number): void {
         }
         return code;
       }
-      for (const server of GetAllServers()) {
+      for (const server of GetAllServers() as unknown as { scripts: Script[] }[]) {
         for (const script of server.scripts) {
           script.code = convert(script.code);
         }
@@ -663,6 +664,15 @@ function evaluateVersionCompatibility(ver: string | number): void {
     }
     anyPlayer.lastAugReset ??= anyPlayer.lastUpdate - anyPlayer.playtimeSinceLastAug;
     anyPlayer.lastNodeReset ??= anyPlayer.lastUpdate - anyPlayer.playtimeSinceLastBitnode;
+    for (const server of GetAllServers()) {
+      if (Array.isArray(server.scripts)) {
+        const oldScripts = server.scripts as Script[];
+        server.scripts = new JSONMap();
+        for (const script of oldScripts) {
+          server.scripts.set(script.filename, script);
+        }
+      }
+    }
   }
 }
 
@@ -673,7 +683,7 @@ function loadGame(saveString: string): boolean {
 
   const saveObj = JSON.parse(saveString, Reviver);
 
-  loadPlayer(saveObj.PlayerSave);
+  setPlayer(loadPlayer(saveObj.PlayerSave));
   loadAllServers(saveObj.AllServersSave);
   loadCompanies(saveObj.CompaniesSave);
   loadFactions(saveObj.FactionsSave);
diff --git a/src/Script/RamCalculations.ts b/src/Script/RamCalculations.ts
index 214a27334..57f5902c0 100644
--- a/src/Script/RamCalculations.ts
+++ b/src/Script/RamCalculations.ts
@@ -12,8 +12,8 @@ import { RamCalculationErrorCode } from "./RamCalculationErrorCodes";
 
 import { RamCosts, RamCostConstants } from "../Netscript/RamCostGenerator";
 import { Script } from "./Script";
-import { areImportsEquals } from "../Terminal/DirectoryHelpers";
 import { Node } from "../NetscriptJSEvaluator";
+import { ScriptFilename, scriptFilenameFromImport } from "../Types/strings";
 
 export interface RamUsageEntry {
   type: "ns" | "dom" | "fn" | "misc";
@@ -40,7 +40,7 @@ const memCheckGlobalKey = ".__GLOBAL__";
  * RAM usage. Also accounts for imported modules.
  * @param {Script[]} otherScripts - All other scripts on the server. Used to account for imported scripts
  * @param {string} code - The code being parsed */
-function parseOnlyRamCalculate(otherScripts: Script[], code: string): RamCalculation {
+function parseOnlyRamCalculate(otherScripts: Map<ScriptFilename, Script>, code: string, ns1?: boolean): RamCalculation {
   try {
     /**
      * Maps dependent identifiers to their dependencies.
@@ -86,16 +86,9 @@ function parseOnlyRamCalculate(otherScripts: Script[], code: string): RamCalcula
       if (nextModule === undefined) throw new Error("nextModule should not be undefined");
       if (nextModule.startsWith("https://") || nextModule.startsWith("http://")) continue;
 
-      let script = null;
-      const fn = nextModule.startsWith("./") ? nextModule.slice(2) : nextModule;
-      for (const s of otherScripts) {
-        if (areImportsEquals(s.filename, fn)) {
-          script = s;
-          break;
-        }
-      }
-
-      if (script == null) {
+      const filename = scriptFilenameFromImport(nextModule, ns1);
+      const script = otherScripts.get(filename);
+      if (!script) {
         return { cost: RamCalculationErrorCode.ImportError }; // No such script on the server
       }
 
@@ -375,9 +368,13 @@ function parseOnlyCalculateDeps(code: string, currentModule: string): ParseDepsR
  * @param {Script[]} otherScripts - All other scripts on the server.
  *                                  Used to account for imported scripts
  */
-export function calculateRamUsage(codeCopy: string, otherScripts: Script[]): RamCalculation {
+export function calculateRamUsage(
+  codeCopy: string,
+  otherScripts: Map<ScriptFilename, Script>,
+  ns1?: boolean,
+): RamCalculation {
   try {
-    return parseOnlyRamCalculate(otherScripts, codeCopy);
+    return parseOnlyRamCalculate(otherScripts, codeCopy, ns1);
   } catch (e) {
     console.error(`Failed to parse script for RAM calculations:`);
     console.error(e);
diff --git a/src/Script/Script.ts b/src/Script/Script.ts
index aab17a168..b2008eef3 100644
--- a/src/Script/Script.ts
+++ b/src/Script/Script.ts
@@ -10,6 +10,7 @@ import { LoadedModule, ScriptURL } from "./LoadedModule";
 import { Generic_fromJSON, Generic_toJSON, IReviverValue, constructorsForReviver } from "../utils/JSONReviver";
 import { roundToTwo } from "../utils/helpers/roundToTwo";
 import { RamCostConstants } from "../Netscript/RamCostGenerator";
+import { ScriptFilename } from "src/Types/strings";
 
 export class Script {
   code: string;
@@ -81,7 +82,7 @@ export class Script {
   }
 
   /** Gets the ram usage, while also attempting to update it if it's currently null */
-  getRamUsage(otherScripts: Script[]): number | null {
+  getRamUsage(otherScripts: Map<ScriptFilename, Script>): number | null {
     if (this.ramUsage) return this.ramUsage;
     this.updateRamUsage(otherScripts);
     return this.ramUsage;
@@ -91,8 +92,8 @@ export class Script {
    * Calculates and updates the script's RAM usage based on its code
    * @param {Script[]} otherScripts - Other scripts on the server. Used to process imports
    */
-  updateRamUsage(otherScripts: Script[]): void {
-    const ramCalc = calculateRamUsage(this.code, otherScripts);
+  updateRamUsage(otherScripts: Map<ScriptFilename, Script>): void {
+    const ramCalc = calculateRamUsage(this.code, otherScripts, this.filename.endsWith(".script"));
     if (ramCalc.cost >= RamCostConstants.Base) {
       this.ramUsage = roundToTwo(ramCalc.cost);
       this.ramUsageEntries = ramCalc.entries as RamUsageEntry[];
diff --git a/src/ScriptEditor/ui/ScriptEditorRoot.tsx b/src/ScriptEditor/ui/ScriptEditorRoot.tsx
index c77893c12..9ac30f80c 100644
--- a/src/ScriptEditor/ui/ScriptEditorRoot.tsx
+++ b/src/ScriptEditor/ui/ScriptEditorRoot.tsx
@@ -432,19 +432,18 @@ export function Root(props: IProps): React.ReactElement {
     if (server === null) throw new Error("Server should not be null but it is.");
     if (isScriptFilename(scriptToSave.fileName)) {
       //If the current script already exists on the server, overwrite it
-      for (let i = 0; i < server.scripts.length; i++) {
-        if (scriptToSave.fileName == server.scripts[i].filename) {
-          server.scripts[i].saveScript(scriptToSave.fileName, scriptToSave.code, Player.currentServer);
-          if (Settings.SaveGameOnFileSave) saveObject.saveGame();
-          Router.toPage(Page.Terminal);
-          return;
-        }
+      const existingScript = server.scripts.get(scriptToSave.fileName);
+      if (existingScript) {
+        existingScript.saveScript(scriptToSave.fileName, scriptToSave.code, Player.currentServer);
+        if (Settings.SaveGameOnFileSave) saveObject.saveGame();
+        Router.toPage(Page.Terminal);
+        return;
       }
 
       //If the current script does NOT exist, create a new one
       const script = new Script();
       script.saveScript(scriptToSave.fileName, scriptToSave.code, Player.currentServer);
-      server.scripts.push(script);
+      server.scripts.set(scriptToSave.fileName, script);
     } else if (scriptToSave.isTxt) {
       for (let i = 0; i < server.textFiles.length; ++i) {
         if (server.textFiles[i].fn === scriptToSave.fileName) {
@@ -509,19 +508,18 @@ export function Root(props: IProps): React.ReactElement {
     if (server === null) throw new Error("Server should not be null but it is.");
     if (isScriptFilename(currentScript.fileName)) {
       //If the current script already exists on the server, overwrite it
-      for (let i = 0; i < server.scripts.length; i++) {
-        if (currentScript.fileName == server.scripts[i].filename) {
-          server.scripts[i].saveScript(currentScript.fileName, currentScript.code, Player.currentServer);
-          if (Settings.SaveGameOnFileSave) saveObject.saveGame();
-          rerender();
-          return;
-        }
+      const existingScript = server.scripts.get(currentScript.fileName);
+      if (existingScript) {
+        existingScript.saveScript(currentScript.fileName, currentScript.code, Player.currentServer);
+        if (Settings.SaveGameOnFileSave) saveObject.saveGame();
+        rerender();
+        return;
       }
 
       //If the current script does NOT exist, create a new one
       const script = new Script();
       script.saveScript(currentScript.fileName, currentScript.code, Player.currentServer);
-      server.scripts.push(script);
+      server.scripts.set(currentScript.fileName, script);
     } else if (currentScript.isTxt) {
       for (let i = 0; i < server.textFiles.length; ++i) {
         if (server.textFiles[i].fn === currentScript.fileName) {
@@ -683,7 +681,7 @@ export function Root(props: IProps): React.ReactElement {
     if (server === null) throw new Error(`Server '${openScript.hostname}' should not be null, but it is.`);
     const data = openScript.isTxt
       ? server.textFiles.find((t) => t.filename === openScript.fileName)?.text
-      : server.scripts.find((s) => s.filename === openScript.fileName)?.code;
+      : server.scripts.get(openScript.fileName)?.code;
     return data ?? null;
   }
   function handleFilterChange(event: React.ChangeEvent<HTMLInputElement>): void {
diff --git a/src/Server/AllServers.ts b/src/Server/AllServers.ts
index f97db369e..f79634a2d 100644
--- a/src/Server/AllServers.ts
+++ b/src/Server/AllServers.ts
@@ -8,11 +8,11 @@ import { IMinMaxRange } from "../types";
 import { createRandomIp } from "../utils/IPAddress";
 import { getRandomInt } from "../utils/helpers/getRandomInt";
 import { Reviver } from "../utils/JSONReviver";
-import { isValidIPAddress } from "../utils/helpers/isValidIPAddress";
 import { SpecialServers } from "./data/SpecialServers";
 import { BitNodeMultipliers } from "../BitNode/BitNodeMultipliers";
 import "../Script/RunningScript"; // For reviver side-effect
 
+import { IPAddress, isIPAddress } from "../Types/strings";
 import type { RunningScript } from "../Script/RunningScript";
 
 /**
@@ -50,9 +50,7 @@ export function GetServer(s: string): BaseServer | null {
     if (server) return server;
   }
 
-  if (!isValidIPAddress(s)) {
-    return GetServerByHostname(s);
-  }
+  if (!isIPAddress(s)) return GetServerByHostname(s);
 
   const ipserver = GetServerByIP(s);
   if (ipserver !== undefined) {
@@ -88,8 +86,8 @@ export function ipExists(ip: string): boolean {
   return false;
 }
 
-export function createUniqueRandomIp(): string {
-  let ip: string;
+export function createUniqueRandomIp(): IPAddress {
+  let ip: IPAddress;
   // Repeat generating ip, until unique one is found
   do {
     ip = createRandomIp();
@@ -117,7 +115,7 @@ export const renameServer = (hostname: string, newName: string): void => {
 interface IServerParams {
   hackDifficulty?: number;
   hostname: string;
-  ip: string;
+  ip: IPAddress;
   maxRam?: number;
   moneyAvailable?: number;
   numOpenPortsRequired: number;
diff --git a/src/Server/BaseServer.ts b/src/Server/BaseServer.ts
index 7e5bbeba5..a3826a015 100644
--- a/src/Server/BaseServer.ts
+++ b/src/Server/BaseServer.ts
@@ -11,11 +11,13 @@ import { isScriptFilename } from "../Script/isScriptFilename";
 import { createRandomIp } from "../utils/IPAddress";
 import { compareArrays } from "../utils/helpers/compareArrays";
 import { ScriptArg } from "../Netscript/ScriptArg";
+import { JSONMap } from "../Types/Jsonable";
+import { IPAddress, ScriptFilename, ServerName } from "../Types/strings";
 
 interface IConstructorParams {
   adminRights?: boolean;
   hostname: string;
-  ip?: string;
+  ip?: IPAddress;
   isConnectedTo?: boolean;
   maxRam?: number;
   organizationName?: string;
@@ -42,13 +44,13 @@ export abstract class BaseServer implements IServer {
   hasAdminRights = false;
 
   // Hostname. Must be unique
-  hostname = "";
+  hostname: ServerName = "home";
 
   // Flag indicating whether HTTP Port is open
   httpPortOpen = false;
 
   // IP Address. Must be unique
-  ip = "";
+  ip = "1.1.1.1" as IPAddress;
 
   // Flag indicating whether player is currently connected to this server
   isConnectedTo = false;
@@ -73,7 +75,7 @@ export abstract class BaseServer implements IServer {
   runningScripts: RunningScript[] = [];
 
   // Script files on this Server
-  scripts: Script[] = [];
+  scripts: JSONMap<ScriptFilename, Script> = new JSONMap();
 
   // Contains the hostnames of all servers that are immediately
   // reachable from this one
@@ -157,13 +159,7 @@ export abstract class BaseServer implements IServer {
    * Script object on the server (if it exists)
    */
   getScript(scriptName: string): Script | null {
-    for (let i = 0; i < this.scripts.length; i++) {
-      if (this.scripts[i].filename === scriptName) {
-        return this.scripts[i];
-      }
-    }
-
-    return null;
+    return this.scripts.get(scriptName) ?? null;
   }
 
   /** Returns boolean indicating whether the given script is running on this server */
@@ -184,44 +180,44 @@ export abstract class BaseServer implements IServer {
 
   /**
    * Remove a file from the server
-   * @param fn {string} Name of file to be deleted
+   * @param filename {string} Name of file to be deleted
    * @returns {IReturnStatus} Return status object indicating whether or not file was deleted
    */
-  removeFile(fn: string): IReturnStatus {
-    if (fn.endsWith(".exe") || fn.match(/^.+\.exe-\d+(?:\.\d*)?%-INC$/) != null) {
+  removeFile(filename: string): IReturnStatus {
+    if (filename.endsWith(".exe") || filename.match(/^.+\.exe-\d+(?:\.\d*)?%-INC$/) != null) {
       for (let i = 0; i < this.programs.length; ++i) {
-        if (this.programs[i] === fn) {
+        if (this.programs[i] === filename) {
           this.programs.splice(i, 1);
           return { res: true };
         }
       }
-    } else if (isScriptFilename(fn)) {
-      const scriptIndex = this.scripts.findIndex((script) => script.filename === fn);
-      if (scriptIndex === -1) return { res: false, msg: `script ${fn} not found.` };
-      if (this.isRunning(fn)) {
+    } else if (isScriptFilename(filename)) {
+      const script = this.scripts.get(filename);
+      if (!script) return { res: false, msg: `script ${filename} not found.` };
+      if (this.isRunning(filename)) {
         return { res: false, msg: "Cannot delete a script that is currently running!" };
       }
-      this.scripts[scriptIndex].invalidateModule();
-      this.scripts.splice(scriptIndex, 1);
+      script.invalidateModule();
+      this.scripts.delete(filename);
       return { res: true };
-    } else if (fn.endsWith(".lit")) {
+    } else if (filename.endsWith(".lit")) {
       for (let i = 0; i < this.messages.length; ++i) {
         const f = this.messages[i];
-        if (typeof f === "string" && f === fn) {
+        if (typeof f === "string" && f === filename) {
           this.messages.splice(i, 1);
           return { res: true };
         }
       }
-    } else if (fn.endsWith(".txt")) {
+    } else if (filename.endsWith(".txt")) {
       for (let i = 0; i < this.textFiles.length; ++i) {
-        if (this.textFiles[i].fn === fn) {
+        if (this.textFiles[i].fn === filename) {
           this.textFiles.splice(i, 1);
           return { res: true };
         }
       }
-    } else if (fn.endsWith(".cct")) {
+    } else if (filename.endsWith(".cct")) {
       for (let i = 0; i < this.contracts.length; ++i) {
-        if (this.contracts[i].fn === fn) {
+        if (this.contracts[i].fn === filename) {
           this.contracts.splice(i, 1);
           return { res: true };
         }
@@ -266,30 +262,23 @@ export abstract class BaseServer implements IServer {
    * Write to a script file
    * Overwrites existing files. Creates new files if the script does not exist.
    */
-  writeToScriptFile(fn: string, code: string): writeResult {
-    const ret = { success: false, overwritten: false };
-    if (!isValidFilePath(fn) || !isScriptFilename(fn)) {
-      return ret;
+  writeToScriptFile(filename: string, code: string): writeResult {
+    if (!isValidFilePath(filename) || !isScriptFilename(filename)) {
+      return { success: false, overwritten: false };
     }
 
     // Check if the script already exists, and overwrite it if it does
-    for (let i = 0; i < this.scripts.length; ++i) {
-      if (fn === this.scripts[i].filename) {
-        const script = this.scripts[i];
-        script.code = code;
-        // Set ramUsage to null in order to force recalculation on next run
-        script.invalidateModule();
-        ret.overwritten = true;
-        ret.success = true;
-        return ret;
-      }
+    const script = this.scripts.get(filename);
+    if (script) {
+      script.invalidateModule();
+      script.code = code;
+      return { success: true, overwritten: true };
     }
 
     // Otherwise, create a new script
-    const newScript = new Script(fn, code, this.hostname);
-    this.scripts.push(newScript);
-    ret.success = true;
-    return ret;
+    const newScript = new Script(filename, code, this.hostname);
+    this.scripts.set(filename, newScript);
+    return { success: true, overwritten: false };
   }
 
   // Write to a text file
diff --git a/src/Server/Server.ts b/src/Server/Server.ts
index 94a974565..1296a32ec 100644
--- a/src/Server/Server.ts
+++ b/src/Server/Server.ts
@@ -6,12 +6,13 @@ import { BitNodeMultipliers } from "../BitNode/BitNodeMultipliers";
 import { createRandomString } from "../utils/helpers/createRandomString";
 import { createRandomIp } from "../utils/IPAddress";
 import { Generic_fromJSON, Generic_toJSON, IReviverValue, constructorsForReviver } from "../utils/JSONReviver";
+import { IPAddress, ServerName } from "../Types/strings";
 
 export interface IConstructorParams {
   adminRights?: boolean;
   hackDifficulty?: number;
   hostname: string;
-  ip?: string;
+  ip?: IPAddress;
   isConnectedTo?: boolean;
   maxRam?: number;
   moneyAvailable?: number;
@@ -60,7 +61,7 @@ export class Server extends BaseServer {
 
     // "hacknet-node-X" hostnames are reserved for Hacknet Servers
     if (this.hostname.startsWith("hacknet-node-") || this.hostname.startsWith("hacknet-server-")) {
-      this.hostname = createRandomString(10);
+      this.hostname = createRandomString(10) as ServerName;
     }
 
     this.purchasedByPlayer = params.purchasedByPlayer != null ? params.purchasedByPlayer : false;
diff --git a/src/Sidebar/ui/SidebarRoot.tsx b/src/Sidebar/ui/SidebarRoot.tsx
index 0a0d1565c..d970c950a 100644
--- a/src/Sidebar/ui/SidebarRoot.tsx
+++ b/src/Sidebar/ui/SidebarRoot.tsx
@@ -143,10 +143,13 @@ export function SidebarRoot(props: IProps): React.ReactElement {
     Player.factions.length > 0 ||
     Player.augmentations.length > 0 ||
     Player.queuedAugmentations.length > 0 ||
-    Player.sourceFiles.length > 0;
+    Player.sourceFiles.size > 0;
 
   const canOpenAugmentations =
-    Player.augmentations.length > 0 || Player.queuedAugmentations.length > 0 || Player.sourceFiles.length > 0;
+    Player.augmentations.length > 0 ||
+    Player.queuedAugmentations.length > 0 ||
+    Player.sourceFiles.size > 0 ||
+    Player.exploits.length > 0;
 
   const canOpenSleeves = Player.sleeves.length > 0;
 
diff --git a/src/SourceFile/PlayerOwnedSourceFile.ts b/src/SourceFile/PlayerOwnedSourceFile.ts
deleted file mode 100644
index 55d99667f..000000000
--- a/src/SourceFile/PlayerOwnedSourceFile.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-export class PlayerOwnedSourceFile {
-  // Source-File level
-  lvl = 1;
-
-  // Source-File number
-  n = 1;
-
-  constructor(n: number, level: number) {
-    this.n = n;
-    this.lvl = level;
-  }
-}
diff --git a/src/SourceFile/applySourceFile.ts b/src/SourceFile/applySourceFile.ts
index b37abac20..ba333f2c3 100644
--- a/src/SourceFile/applySourceFile.ts
+++ b/src/SourceFile/applySourceFile.ts
@@ -1,21 +1,20 @@
-import { PlayerOwnedSourceFile } from "./PlayerOwnedSourceFile";
 import { SourceFiles } from "./SourceFiles";
 
 import { Player } from "@player";
 
-export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
-  const srcFileKey = "SourceFile" + srcFile.n;
+export function applySourceFile(bn: number, lvl: number): void {
+  const srcFileKey = "SourceFile" + bn;
   const sourceFileObject = SourceFiles[srcFileKey];
   if (sourceFileObject == null) {
-    console.error(`Invalid source file number: ${srcFile.n}`);
+    console.error(`Invalid source file number: ${bn}`);
     return;
   }
 
-  switch (srcFile.n) {
+  switch (bn) {
     case 1: {
       // The Source Genesis
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 16 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -51,7 +50,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 2: {
       // Rise of the Underworld
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 24 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -63,7 +62,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 3: {
       // Corporatocracy
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 8 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -79,7 +78,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 5: {
       // Artificial Intelligence
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 8 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -94,7 +93,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 6: {
       // Bladeburner
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 8 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -111,7 +110,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 7: {
       // Bladeburner 2079
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 8 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -124,7 +123,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 8: {
       // Ghost of Wall Street
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 12 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -134,7 +133,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 9: {
       // Hacktocracy
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 12 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -154,7 +153,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
     case 11: {
       // The Big Crash
       let mult = 0;
-      for (let i = 0; i < srcFile.lvl; ++i) {
+      for (let i = 0; i < lvl; ++i) {
         mult += 32 / Math.pow(2, i);
       }
       const incMult = 1 + mult / 100;
@@ -169,7 +168,7 @@ export function applySourceFile(srcFile: PlayerOwnedSourceFile): void {
       // Grants more space on Stanek's Gift.
       break;
     default:
-      console.error(`Invalid source file number: ${srcFile.n}`);
+      console.error(`Invalid source file number: ${bn}`);
       break;
   }
 
diff --git a/src/Terminal/DirectoryServerHelpers.ts b/src/Terminal/DirectoryServerHelpers.ts
index 9e4b01db3..b3de7c33c 100644
--- a/src/Terminal/DirectoryServerHelpers.ts
+++ b/src/Terminal/DirectoryServerHelpers.ts
@@ -41,8 +41,8 @@ export function getSubdirectories(serv: BaseServer, dir: string): string[] {
     }
   }
 
-  for (const script of serv.scripts) {
-    processFile(script.filename);
+  for (const scriptFilename of serv.scripts.keys()) {
+    processFile(scriptFilename);
   }
 
   for (const txt of serv.textFiles) {
@@ -56,7 +56,7 @@ export function getSubdirectories(serv: BaseServer, dir: string): string[] {
 export function containsFiles(server: BaseServer, dir: string): boolean {
   const dirWithTrailingSlash = dir + (dir.slice(-1) === "/" ? "" : "/");
 
-  return [...server.scripts.map((s) => s.filename), ...server.textFiles.map((t) => t.fn)].some((filename) =>
+  return [...server.scripts.keys(), ...server.textFiles.map((t) => t.fn)].some((filename) =>
     filename.startsWith(dirWithTrailingSlash),
   );
 }
diff --git a/src/Terminal/Terminal.ts b/src/Terminal/Terminal.ts
index d133c328f..99af32483 100644
--- a/src/Terminal/Terminal.ts
+++ b/src/Terminal/Terminal.ts
@@ -400,16 +400,10 @@ export class Terminal {
   }
 
   getScript(filename: string): Script | null {
-    const s = Player.getCurrentServer();
+    const server = Player.getCurrentServer();
     const filepath = this.getFilepath(filename);
-    if (!filepath) return null;
-    for (const script of s.scripts) {
-      if (filepath === script.filename) {
-        return script;
-      }
-    }
-
-    return null;
+    if (filepath === null) return null;
+    return server.scripts.get(filepath) ?? null;
   }
 
   getTextFile(filename: string): TextFile | null {
diff --git a/src/Terminal/commands/common/editor.ts b/src/Terminal/commands/common/editor.ts
index e639d6405..ac8346640 100644
--- a/src/Terminal/commands/common/editor.ts
+++ b/src/Terminal/commands/common/editor.ts
@@ -7,6 +7,7 @@ import { isScriptFilename } from "../../../Script/isScriptFilename";
 import { CursorPositions } from "../../../ScriptEditor/CursorPositions";
 import { Script } from "../../../Script/Script";
 import { isEmpty } from "lodash";
+import { ScriptFilename } from "src/Types/strings";
 
 interface EditorParameters {
   args: (string | number | boolean)[];
@@ -28,7 +29,7 @@ interface ISimpleScriptGlob {
   postGlob: string;
   globError: string;
   globMatches: string[];
-  globAgainst: Script[];
+  globAgainst: Map<ScriptFilename, Script>;
 }
 
 function containsSimpleGlob(filename: string): boolean {
@@ -45,7 +46,7 @@ function detectSimpleScriptGlob({ args, server }: EditorParameters): ISimpleScri
   return null;
 }
 
-function parseSimpleScriptGlob(globString: string, globDatabase: Script[]): ISimpleScriptGlob {
+function parseSimpleScriptGlob(globString: string, globDatabase: Map<ScriptFilename, Script>): ISimpleScriptGlob {
   const parsedGlob: ISimpleScriptGlob = {
     glob: globString,
     preGlob: "",
diff --git a/src/Terminal/commands/cp.ts b/src/Terminal/commands/cp.ts
index 5a5d0b4d7..f14b0d9a8 100644
--- a/src/Terminal/commands/cp.ts
+++ b/src/Terminal/commands/cp.ts
@@ -56,17 +56,8 @@ export function cp(args: (string | number | boolean)[], server: BaseServer): voi
     }
 
     // Get the current script
-    let sourceScript = null;
-    for (let i = 0; i < server.scripts.length; ++i) {
-      if (areFilesEqual(server.scripts[i].filename, src)) {
-        sourceScript = server.scripts[i];
-        break;
-      }
-    }
-    if (sourceScript == null) {
-      Terminal.error("cp failed. No such script exists");
-      return;
-    }
+    const sourceScript = server.scripts.get(src);
+    if (!sourceScript) return Terminal.error("cp failed. No such script exists");
 
     const sRes = server.writeToScriptFile(dst, sourceScript.code);
     if (!sRes.success) {
diff --git a/src/Terminal/commands/download.ts b/src/Terminal/commands/download.ts
index 6a0902639..2370b8624 100644
--- a/src/Terminal/commands/download.ts
+++ b/src/Terminal/commands/download.ts
@@ -19,8 +19,8 @@ export function exportScripts(pattern: string, server: BaseServer): void {
   // In the case of script files, we pull from the server.scripts array
   if (!matchEnding || isScriptFilename(matchEnding))
     zipFiles(
-      server.scripts.map((s) => s.filename),
-      server.scripts.map((s) => s.code),
+      [...server.scripts.keys()],
+      [...server.scripts.values()].map((script) => script.code),
     );
   // In the case of text files, we pull from the server.scripts array
   if (!matchEnding || matchEnding.endsWith(".txt"))
diff --git a/src/Terminal/commands/ls.tsx b/src/Terminal/commands/ls.tsx
index bb65f970c..cbdae5a8e 100644
--- a/src/Terminal/commands/ls.tsx
+++ b/src/Terminal/commands/ls.tsx
@@ -106,7 +106,7 @@ export function ls(args: (string | number | boolean)[], server: BaseServer): voi
 
   // Get all of the programs and scripts on the machine into one temporary array
   for (const program of server.programs) handleFn(program, allPrograms);
-  for (const script of server.scripts) handleFn(script.filename, allScripts);
+  for (const scriptFilename of server.scripts.keys()) handleFn(scriptFilename, allScripts);
   for (const txt of server.textFiles) handleFn(txt.fn, allTextFiles);
   for (const contract of server.contracts) handleFn(contract.fn, allContracts);
   for (const msgOrLit of server.messages) handleFn(msgOrLit, allMessages);
diff --git a/src/Terminal/commands/runScript.ts b/src/Terminal/commands/runScript.ts
index 7e2b7ad6d..c2b1b0a84 100644
--- a/src/Terminal/commands/runScript.ts
+++ b/src/Terminal/commands/runScript.ts
@@ -43,50 +43,43 @@ export function runScript(commandArgs: (string | number | boolean)[], server: Ba
   }
 
   // Check if the script exists and if it does run it
-  for (let i = 0; i < server.scripts.length; i++) {
-    if (server.scripts[i].filename !== scriptName) {
-      continue;
-    }
-    // Check for admin rights and that there is enough RAM available to run
-    const script = server.scripts[i];
-    script.server = server.hostname;
-    const singleRamUsage = script.getRamUsage(server.scripts);
-    if (!singleRamUsage) return Terminal.error("Error while calculating ram usage for this script.");
-    const ramUsage = singleRamUsage * numThreads;
-    const ramAvailable = server.maxRam - server.ramUsed;
+  const script = server.scripts.get(scriptName);
+  if (!script) return Terminal.error("No such script");
 
-    if (!server.hasAdminRights) {
-      Terminal.error("Need root access to run script");
-      return;
-    }
+  const singleRamUsage = script.getRamUsage(server.scripts);
+  if (!singleRamUsage) return Terminal.error("Error while calculating ram usage for this script.");
+  const ramUsage = singleRamUsage * numThreads;
+  const ramAvailable = server.maxRam - server.ramUsed;
 
-    if (ramUsage > ramAvailable + 0.001) {
-      Terminal.error(
-        "This machine does not have enough RAM to run this script" +
-          (numThreads === 1 ? "" : ` with ${numThreads} threads`) +
-          `. Script requires ${formatRam(ramUsage)} of RAM`,
-      );
-      return;
-    }
-
-    // Able to run script
-    const runningScript = new RunningScript(script, singleRamUsage, args);
-    runningScript.threads = numThreads;
-
-    const success = startWorkerScript(runningScript, server);
-    if (!success) {
-      Terminal.error(`Failed to start script`);
-      return;
-    }
-
-    Terminal.print(
-      `Running script with ${numThreads} thread(s), pid ${runningScript.pid} and args: ${JSON.stringify(args)}.`,
-    );
-    if (tailFlag) {
-      LogBoxEvents.emit(runningScript);
-    }
+  if (!server.hasAdminRights) {
+    Terminal.error("Need root access to run script");
     return;
   }
 
-  Terminal.error("No such script");
+  if (ramUsage > ramAvailable + 0.001) {
+    Terminal.error(
+      "This machine does not have enough RAM to run this script" +
+        (numThreads === 1 ? "" : ` with ${numThreads} threads`) +
+        `. Script requires ${formatRam(ramUsage)} of RAM`,
+    );
+    return;
+  }
+
+  // Able to run script
+  const runningScript = new RunningScript(script, singleRamUsage, args);
+  runningScript.threads = numThreads;
+
+  const success = startWorkerScript(runningScript, server);
+  if (!success) {
+    Terminal.error(`Failed to start script`);
+    return;
+  }
+
+  Terminal.print(
+    `Running script with ${numThreads} thread(s), pid ${runningScript.pid} and args: ${JSON.stringify(args)}.`,
+  );
+  if (tailFlag) {
+    LogBoxEvents.emit(runningScript);
+  }
+  return;
 }
diff --git a/src/Terminal/commands/scp.ts b/src/Terminal/commands/scp.ts
index ab53413e5..d4457ac36 100644
--- a/src/Terminal/commands/scp.ts
+++ b/src/Terminal/commands/scp.ts
@@ -51,11 +51,8 @@ export function scp(args: (string | number | boolean)[], server: BaseServer): vo
     }
 
     // Get the current script
-    const sourceScript = server.scripts.find((script) => script.filename === scriptname);
-    if (!sourceScript) {
-      Terminal.error("scp failed. No such script exists");
-      return;
-    }
+    const sourceScript = server.scripts.get(scriptname);
+    if (!sourceScript) return Terminal.error("scp failed. No such script exists");
 
     const sRes = destServer.writeToScriptFile(scriptname, sourceScript.code);
     if (!sRes.success) {
diff --git a/src/Terminal/determineAllPossibilitiesForTabCompletion.ts b/src/Terminal/determineAllPossibilitiesForTabCompletion.ts
index 99b98dc1d..fa1c3c6e0 100644
--- a/src/Terminal/determineAllPossibilitiesForTabCompletion.ts
+++ b/src/Terminal/determineAllPossibilitiesForTabCompletion.ts
@@ -101,8 +101,8 @@ export async function determineAllPossibilitiesForTabCompletion(
   }
 
   function addAllScripts(): void {
-    for (const script of currServ.scripts) {
-      const res = processFilepath(script.filename);
+    for (const scriptFilename of currServ.scripts.keys()) {
+      const res = processFilepath(scriptFilename);
       if (res) {
         allPos.push(res);
       }
@@ -281,10 +281,7 @@ export async function determineAllPossibilitiesForTabCompletion(
     // Use regex to remove any leading './', and then check if it matches against
     // the output of processFilepath or if it matches with a '/' prepended,
     // this way autocomplete works inside of directories
-    const script = currServ.scripts.find((script) => {
-      const fn = filename.replace(/^\.\//g, "");
-      return processFilepath(script.filename) === fn || script.filename === "/" + fn;
-    });
+    const script = currServ.scripts.get(filename);
     if (!script) return; // Doesn't exist.
     let loadedModule;
     try {
@@ -304,7 +301,7 @@ export async function determineAllPossibilitiesForTabCompletion(
     const flagFunc = Flags(flags._);
     const autocompleteData: AutocompleteData = {
       servers: GetAllServers().map((server) => server.hostname),
-      scripts: currServ.scripts.map((script) => script.filename),
+      scripts: [...currServ.scripts.keys()],
       txts: currServ.textFiles.map((txt) => txt.fn),
       flags: (schema: unknown) => {
         if (!Array.isArray(schema)) throw new Error("flags require an array of array");
@@ -334,8 +331,8 @@ export async function determineAllPossibilitiesForTabCompletion(
   // invocation of `run`.
   if (input.startsWith("./")) {
     // All programs and scripts
-    for (const script of currServ.scripts) {
-      const res = processFilepath(script.filename);
+    for (const scriptFilename of currServ.scripts.keys()) {
+      const res = processFilepath(scriptFilename);
       if (res) {
         allPos.push(res);
       }
diff --git a/src/Types/Jsonable.ts b/src/Types/Jsonable.ts
new file mode 100644
index 000000000..d083bcc17
--- /dev/null
+++ b/src/Types/Jsonable.ts
@@ -0,0 +1,20 @@
+import type { IReviverValue } from "../utils/JSONReviver";
+// Jsonable versions of builtin JS class objects
+export class JSONSet<T> extends Set<T> {
+  toJSON(): IReviverValue {
+    return { ctor: "JSONSet", data: Array.from(this) };
+  }
+  static fromJSON(value: IReviverValue): JSONSet<any> {
+    return new JSONSet(value.data);
+  }
+}
+
+export class JSONMap<K, V> extends Map<K, V> {
+  toJSON(): IReviverValue {
+    return { ctor: "JSONMap", data: Array.from(this) };
+  }
+
+  static fromJSON(value: IReviverValue): JSONMap<any, any> {
+    return new JSONMap(value.data);
+  }
+}
diff --git a/src/Types/strings.ts b/src/Types/strings.ts
new file mode 100644
index 000000000..7484d9bc1
--- /dev/null
+++ b/src/Types/strings.ts
@@ -0,0 +1,29 @@
+// Script Filename
+export type ScriptFilename = string /*& { __type: "ScriptFilename" }*/;
+/*export function isScriptFilename(value: string): value is ScriptFilename {
+  // implementation
+}*/
+/*export function sanitizeScriptFilename(filename: string): ScriptFilename {
+  // implementation
+}*/
+export function scriptFilenameFromImport(importPath: string, ns1?: boolean): ScriptFilename {
+  if (importPath.startsWith("./")) importPath = importPath.substring(2);
+  if (!ns1 && !importPath.endsWith(".js")) importPath += ".js";
+  if (ns1 && !importPath.endsWith(".script")) importPath += ".script";
+  return importPath as ScriptFilename;
+}
+
+// Server name
+export type ServerName = string /*& { __type: "ServerName" }*/;
+/*export function isExistingServerName(value: unknown): value is ServerName {
+  if (AllServers.has(value as ServerName)) return true; // For AllServers as an exported map
+  return false;
+}*/
+
+// IP Address
+export type IPAddress = string /*& { __type: "IPAddress" }*/;
+export function isIPAddress(value: string): value is IPAddress {
+  const regex =
+    /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
+  return regex.test(value);
+}
diff --git a/src/engine.tsx b/src/engine.tsx
index 4a646de1a..c61976c16 100644
--- a/src/engine.tsx
+++ b/src/engine.tsx
@@ -255,21 +255,19 @@ const Engine: {
       const contractChancesWhileOffline = Math.floor(timeOffline / (1000 * 60 * 10));
 
       // Generate coding contracts
-      if (Player.sourceFiles.length > 0) {
-        let numContracts = 0;
-        if (contractChancesWhileOffline > 100) {
-          numContracts += Math.floor(contractChancesWhileOffline * 0.25);
-        }
-        if (contractChancesWhileOffline > 0 && contractChancesWhileOffline <= 100) {
-          for (let i = 0; i < contractChancesWhileOffline; ++i) {
-            if (Math.random() <= 0.25) {
-              numContracts++;
-            }
+      let numContracts = 0;
+      if (contractChancesWhileOffline > 100) {
+        numContracts += Math.floor(contractChancesWhileOffline * 0.25);
+      }
+      if (contractChancesWhileOffline > 0 && contractChancesWhileOffline <= 100) {
+        for (let i = 0; i < contractChancesWhileOffline; ++i) {
+          if (Math.random() <= 0.25) {
+            numContracts++;
           }
         }
-        for (let i = 0; i < numContracts; i++) {
-          generateRandomContract();
-        }
+      }
+      for (let i = 0; i < numContracts; i++) {
+        generateRandomContract();
       }
 
       let offlineReputation = 0;
diff --git a/src/ui/CharacterStats.tsx b/src/ui/CharacterStats.tsx
index 2d6a1a12b..8b035f8eb 100644
--- a/src/ui/CharacterStats.tsx
+++ b/src/ui/CharacterStats.tsx
@@ -84,7 +84,7 @@ function MultiplierTable(props: MultTableProps): React.ReactElement {
 }
 
 function CurrentBitNode(): React.ReactElement {
-  if (Player.sourceFiles.length > 0) {
+  if (Player.sourceFiles.size > 0) {
     const index = "BitNode" + Player.bitNodeN;
     const lvl = Math.min(Player.sourceFileLvl(Player.bitNodeN) + 1, Player.bitNodeN === 12 ? Infinity : 3);
     return (
@@ -175,7 +175,7 @@ function MoneyModal({ open, onClose }: IMoneyModalProps): React.ReactElement {
       {convertMoneySourceTrackerToString(Player.moneySourceA)}
     </>
   );
-  if (Player.sourceFiles.length !== 0) {
+  if (Player.sourceFiles.size > 0) {
     content = (
       <>
         {content}
@@ -205,7 +205,7 @@ export function CharacterStats(): React.ReactElement {
   const timeRows = [
     ["Since last Augmentation installation", convertTimeMsToTimeElapsedString(Player.playtimeSinceLastAug)],
   ];
-  if (Player.sourceFiles.length > 0) {
+  if (Player.sourceFiles.size > 0) {
     timeRows.push(["Since last Bitnode destroyed", convertTimeMsToTimeElapsedString(Player.playtimeSinceLastBitnode)]);
   }
   timeRows.push(["Total", convertTimeMsToTimeElapsedString(Player.totalPlaytime)]);
diff --git a/src/ui/React/LogBoxManager.tsx b/src/ui/React/LogBoxManager.tsx
index e5f281b81..94f14591e 100644
--- a/src/ui/React/LogBoxManager.tsx
+++ b/src/ui/React/LogBoxManager.tsx
@@ -20,7 +20,6 @@ import { Settings } from "../../Settings/Settings";
 import { ANSIITypography } from "./ANSIITypography";
 import { ScriptArg } from "../../Netscript/ScriptArg";
 import { useRerender } from "./hooks";
-import { areFilesEqual } from "../../Terminal/DirectoryHelpers";
 import { dialogBoxCreate } from "./DialogBox";
 
 let layerCounter = 0;
@@ -222,7 +221,7 @@ function LogWindow(props: IProps): React.ReactElement {
     if (server === null) return;
     const s = findRunningScript(script.filename, script.args, server);
     if (s === null) {
-      const baseScript = server.scripts.find((serverScript) => areFilesEqual(serverScript.filename, script.filename));
+      const baseScript = server.scripts.get(script.filename);
       if (!baseScript) {
         return dialogBoxCreate(
           `Could not launch script. The script ${script.filename} no longer exists on the server ${server.hostname}.`,
diff --git a/src/utils/IPAddress.ts b/src/utils/IPAddress.ts
index 325712bea..9034308f0 100644
--- a/src/utils/IPAddress.ts
+++ b/src/utils/IPAddress.ts
@@ -1,8 +1,9 @@
+import { IPAddress } from "src/Types/strings";
 import { getRandomByte } from "./helpers/getRandomByte";
 
 /**
  * Generate a random IP address
  * Does not check to see if the IP already exists in the game
  */
-export const createRandomIp = (): string =>
-  `${getRandomByte(99)}.${getRandomByte(9)}.${getRandomByte(9)}.${getRandomByte(9)}`;
+export const createRandomIp = (): IPAddress =>
+  `${getRandomByte(99)}.${getRandomByte(9)}.${getRandomByte(9)}.${getRandomByte(9)}` as IPAddress;
diff --git a/src/utils/JSONReviver.ts b/src/utils/JSONReviver.ts
index bf0ab86d2..a81e7db0b 100644
--- a/src/utils/JSONReviver.ts
+++ b/src/utils/JSONReviver.ts
@@ -1,6 +1,11 @@
 /* Generic Reviver, toJSON, and fromJSON functions used for saving and loading objects */
-
 import { ObjectValidator, validateObject } from "./Validator";
+import { JSONMap, JSONSet } from "../Types/Jsonable";
+
+type JsonableClass = (new () => { toJSON: () => IReviverValue }) & {
+  fromJSON: (value: IReviverValue) => any;
+  validationData?: ObjectValidator<any>;
+};
 
 export interface IReviverValue {
   ctor: string;
@@ -38,15 +43,7 @@ export function Reviver(_key: string, value: unknown): any {
   return obj;
 }
 
-export const constructorsForReviver: Partial<
-  Record<
-    string,
-    (new () => object) & {
-      fromJSON: (value: IReviverValue) => any;
-      validationData?: ObjectValidator<any>;
-    }
-  >
-> = {};
+export const constructorsForReviver: Partial<Record<string, JsonableClass>> = { JSONSet, JSONMap };
 
 /**
  * A generic "toJSON" function that creates the data expected by Reviver.
diff --git a/src/utils/helpers/isValidIPAddress.ts b/src/utils/helpers/isValidIPAddress.ts
deleted file mode 100644
index 6d8395c03..000000000
--- a/src/utils/helpers/isValidIPAddress.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-/**
- * Checks whether a IP Address string is valid.
- * @param ipaddress A string representing a potential IP Address
- */
-export function isValidIPAddress(ipaddress: string): boolean {
-  const byteRange = "(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";
-  const regexStr = `^${byteRange}\.${byteRange}\.${byteRange}\.${byteRange}$`;
-  const ipAddressRegex = new RegExp(regexStr);
-
-  return ipAddressRegex.test(ipaddress);
-}
diff --git a/src/utils/v1APIBreak.ts b/src/utils/v1APIBreak.ts
index a86b7456f..bd1446621 100644
--- a/src/utils/v1APIBreak.ts
+++ b/src/utils/v1APIBreak.ts
@@ -95,7 +95,11 @@ export function v1APIBreak(): void {
   for (const server of GetAllServers()) {
     for (const change of detect) {
       const s: IFileLine[] = [];
-      for (const script of server.scripts) {
+      const scriptsArray: Script[] = Array.isArray(server.scripts)
+        ? (server.scripts as Script[])
+        : [...server.scripts.values()];
+
+      for (const script of scriptsArray) {
         const lines = script.code.split("\n");
         for (let i = 0; i < lines.length; i++) {
           if (lines[i].includes(change[0])) {
@@ -121,7 +125,8 @@ export function v1APIBreak(): void {
     home.writeToTextFile("v1_DETECTED_CHANGES.txt", txt);
   }
 
-  for (const server of GetAllServers()) {
+  // API break function is called before version31 / 2.3.0 changes - scripts is still an array
+  for (const server of GetAllServers() as unknown as { scripts: Script[] }[]) {
     const backups: Script[] = [];
     for (const script of server.scripts) {
       if (!hasChanges(script.code)) continue;
diff --git a/src/utils/v2APIBreak.ts b/src/utils/v2APIBreak.ts
index 8e9219b67..f26b5977f 100644
--- a/src/utils/v2APIBreak.ts
+++ b/src/utils/v2APIBreak.ts
@@ -227,7 +227,8 @@ export const v2APIBreak = () => {
     });
   }
 
-  for (const script of home.scripts) {
+  // API break function is called before the version31 2.3.0 changes, scripts are still an array.
+  for (const script of home.scripts as unknown as Script[]) {
     processScript(rules, script);
   }
 
diff --git a/test/jest/Netscript/RamCalculation.test.ts b/test/jest/Netscript/RamCalculation.test.ts
index 89a27c086..2c107cf0d 100644
--- a/test/jest/Netscript/RamCalculation.test.ts
+++ b/test/jest/Netscript/RamCalculation.test.ts
@@ -27,9 +27,8 @@ function isRemovedFunction(ctx: NetscriptContext, fn: (ctx: NetscriptContext) =>
 }
 
 describe("Netscript RAM Calculation/Generation Tests", function () {
-  Player.sourceFiles[0] = { n: 4, lvl: 3 };
+  Player.sourceFiles.set(4, 3);
   // For simulating costs of singularity functions.
-  const sf4 = Player.sourceFiles[0];
   const baseCost = RamCostConstants.Base;
   const maxCost = RamCostConstants.Max;
   const script = new Script();
@@ -38,7 +37,7 @@ describe("Netscript RAM Calculation/Generation Tests", function () {
     script.code = code;
     // Force ram calculation reset
     script.ramUsage = null;
-    const ramUsage = script.getRamUsage([]);
+    const ramUsage = script.getRamUsage(new Map());
     if (!ramUsage) throw new Error("Ram usage should be defined.");
     const runningScript = new RunningScript(script, ramUsage);
     return runningScript;
@@ -63,7 +62,7 @@ describe("Netscript RAM Calculation/Generation Tests", function () {
     ramUsage: scriptRef.ramUsage,
     scriptRef,
   };
-  const nsExternal = NetscriptFunctions(workerScript as WorkerScript);
+  const nsExternal = NetscriptFunctions(workerScript as unknown as WorkerScript);
 
   function combinedRamCheck(
     fn: PotentiallyAsyncFunction,
@@ -78,7 +77,7 @@ describe("Netscript RAM Calculation/Generation Tests", function () {
     expect(getRamCost(...fnPath)).toEqual(expectedRamCost);
 
     // Static ram check
-    const staticCost = calculateRamUsage(code, []).cost;
+    const staticCost = calculateRamUsage(code, new Map()).cost;
     expect(staticCost).toBeCloseTo(Math.min(baseCost + expectedRamCost + extraLayerCost, maxCost));
 
     // reset workerScript for dynamic check
@@ -144,7 +143,7 @@ describe("Netscript RAM Calculation/Generation Tests", function () {
 
   describe("Singularity multiplier checks", () => {
     // Checks were already done above for SF4.3 having normal ramcost.
-    sf4.lvl = 3;
+    Player.sourceFiles.set(4, 3);
     const lvlToMult = { 0: 16, 1: 16, 2: 4 };
     const externalSingularity = nsExternal.singularity;
     const ramCostSingularity = RamCosts.singularity;
@@ -160,7 +159,7 @@ describe("Netscript RAM Calculation/Generation Tests", function () {
       });
     for (const lvl of [0, 1, 2] as const) {
       it(`SF4.${lvl} check for x${lvlToMult[lvl]} costs`, () => {
-        sf4.lvl = lvl;
+        Player.sourceFiles.set(4, lvl);
         const expectedMult = lvlToMult[lvl];
         singObjects.forEach(({ name, baseRam }) => {
           const fn = getFunction(externalSingularity[name]);
diff --git a/test/jest/Netscript/RunScript.test.ts b/test/jest/Netscript/RunScript.test.ts
index 17faca6b7..e65a83fc0 100644
--- a/test/jest/Netscript/RunScript.test.ts
+++ b/test/jest/Netscript/RunScript.test.ts
@@ -5,6 +5,7 @@ import { RunningScript } from "../../../src/Script/RunningScript";
 import { AddToAllServers, DeleteServer } from "../../../src/Server/AllServers";
 import { WorkerScriptStartStopEventEmitter } from "../../../src/Netscript/WorkerScriptStartStopEventEmitter";
 import { AlertEvents } from "../../../src/ui/React/AlertManager";
+import type { Script } from "src/Script/Script";
 
 // Replace Blob/ObjectURL functions, because they don't work natively in Jest
 global.Blob = class extends Blob {
@@ -89,10 +90,11 @@ test.each([
       expect(server.writeToScriptFile(s.name, s.code)).toEqual({ success: true, overwritten: false });
     }
 
-    const script = server.scripts[server.scripts.length - 1];
+    const script = server.scripts.get(scripts[scripts.length - 1].name) as Script;
     expect(script.filename).toEqual(scripts[scripts.length - 1].name);
 
     const ramUsage = script.getRamUsage(server.scripts);
+    if (!ramUsage) throw new Error(`ramUsage calculated to be ${ramUsage}`);
     const runningScript = new RunningScript(script, ramUsage as number);
     expect(startWorkerScript(runningScript, server)).toBeGreaterThan(0);
     // We don't care about start, so subscribe after that. Await script death.
diff --git a/test/jest/Netscript/StaticRamParsingCalculation.test.ts b/test/jest/Netscript/StaticRamParsingCalculation.test.ts
index 6dfaf11f8..296f21a83 100644
--- a/test/jest/Netscript/StaticRamParsingCalculation.test.ts
+++ b/test/jest/Netscript/StaticRamParsingCalculation.test.ts
@@ -21,7 +21,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
       const code = `
         export async function main(ns) { }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, 0);
     });
 
@@ -31,7 +31,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           ns.print("Slum snakes r00l!");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, 0);
     });
 
@@ -41,7 +41,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await ns.hack("joesguns");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -51,7 +51,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await X.hack("joesguns");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -62,7 +62,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await ns.hack("joesguns");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -73,7 +73,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await ns.grow("joesguns");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost + GrowCost);
     });
 
@@ -86,7 +86,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await ns.hack("joesguns");
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -101,7 +101,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           async doHacking() { await this.ns.hack("joesguns"); }
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -116,7 +116,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           async doHacking() { await this.#ns.hack("joesguns"); }
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HackCost);
     });
   });
@@ -129,7 +129,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
         }
         function get() { return 0; }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, 0);
     });
 
@@ -140,7 +140,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
         }
         function purchaseNode() { return 0; }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       // Works at present, because the parser checks the namespace only, not the function name
       expectCost(calculated, 0);
     });
@@ -153,7 +153,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
         }
         function getTask() { return 0; }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, 0);
     });
   });
@@ -165,7 +165,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           ns.hacknet.purchaseNode(0);
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, HacknetCost);
     });
 
@@ -175,7 +175,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           ns.corporation.getCorporation();
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, MaxCost);
     });
 
@@ -186,7 +186,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           ns.corporation.getCorporation();
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, MaxCost);
     });
 
@@ -196,7 +196,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           ns.sleeve.getTask(3);
         }
       `;
-      const calculated = calculateRamUsage(code, []).cost;
+      const calculated = calculateRamUsage(code, new Map()).cost;
       expectCost(calculated, SleeveGetTaskCost);
     });
   });
@@ -214,7 +214,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           dummy();
         }
       `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, 0);
     });
 
@@ -230,7 +230,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await doHack(ns);
         }
       `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -247,7 +247,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await doHack(ns);
         }
       `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -264,7 +264,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await test.doHack(ns);
         }
       `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, HackCost + GrowCost);
     });
 
@@ -286,7 +286,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
           await test.doHack(ns);
         }
       `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, HackCost);
     });
 
@@ -312,7 +312,7 @@ describe("Parsing NetScript code to work out static RAM costs", function () {
             await growerInstance.doGrow();
           }
         `;
-      const calculated = calculateRamUsage(code, [lib]).cost;
+      const calculated = calculateRamUsage(code, new Map([["libTest.js", lib]])).cost;
       expectCost(calculated, GrowCost);
     });
   });
diff --git a/test/jest/__snapshots__/Save.test.ts.snap b/test/jest/__snapshots__/Save.test.ts.snap
index e10bc4680..36e1fa7b0 100644
--- a/test/jest/__snapshots__/Save.test.ts.snap
+++ b/test/jest/__snapshots__/Save.test.ts.snap
@@ -89,7 +89,10 @@ exports[`load/saveAllServers 1`] = `
       "programs": [],
       "ramUsed": 0,
       "runningScripts": [],
-      "scripts": [],
+      "scripts": {
+        "ctor": "JSONMap",
+        "data": []
+      },
       "serversOnNetwork": [
         "home"
       ],
@@ -183,7 +186,10 @@ exports[`load/saveAllServers pruning RunningScripts 1`] = `
       "programs": [],
       "ramUsed": 0,
       "runningScripts": [],
-      "scripts": [],
+      "scripts": {
+        "ctor": "JSONMap",
+        "data": []
+      },
       "serversOnNetwork": [
         "home"
       ],