diff --git a/.gitignore b/.gitignore
index a835d8d8..e48470ef 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@ node_modules/
 .lock-wscript
 lib/
 out/
+out-demo/
 out-test/
 out-esbuild/
 out-esbuild-test/
diff --git a/demo/client/client.ts b/demo/client/client.ts
index 5d2f34f3..2571e73b 100644
--- a/demo/client/client.ts
+++ b/demo/client/client.ts
@@ -5,19 +5,15 @@
  * This file is the entry point for browserify.
  */
 
-/// <reference path="../typings/xterm.d.ts"/>
-
-/* eslint-disable no-restricted-syntax */
-
 // HACK: Playwright/WebKit on Windows does not support WebAssembly https://stackoverflow.com/q/62311688/1156119
-import type { ImageAddon as ImageAddonType, IImageAddonOptions } from '@xterm/addon-image';
+import type { ImageAddon as ImageAddonType } from '@xterm/addon-image';
 let ImageAddon: typeof ImageAddonType | undefined; // eslint-disable-line @typescript-eslint/naming-convention
 if ('WebAssembly' in window) {
   const imageAddon = require('@xterm/addon-image');
   ImageAddon = imageAddon.ImageAddon;
 }
 
-import { Terminal, ITerminalOptions, type IDisposable, type ITheme } from '@xterm/xterm';
+import { Terminal, ITerminalOptions, type ITheme } from '@xterm/xterm';
 import { AttachAddon } from '@xterm/addon-attach';
 import { AddonsWindow } from './components/window/addonsWindow';
 import { ControlBar } from './components/controlBar';
@@ -29,31 +25,30 @@ import { VtWindow } from './components/window/vtWindow';
 import { ClipboardAddon } from '@xterm/addon-clipboard';
 import { FitAddon } from '@xterm/addon-fit';
 import { LigaturesAddon } from '@xterm/addon-ligatures';
-import { ProgressAddon, IProgressState } from '@xterm/addon-progress';
+import { ProgressAddon } from '@xterm/addon-progress';
 import { SearchAddon, ISearchOptions } from '@xterm/addon-search';
 import { SerializeAddon } from '@xterm/addon-serialize';
 import { WebLinksAddon } from '@xterm/addon-web-links';
 import { WebglAddon } from '@xterm/addon-webgl';
 import { Unicode11Addon } from '@xterm/addon-unicode11';
 import { UnicodeGraphemesAddon } from '@xterm/addon-unicode-graphemes';
-
 import { AddonCollection, type AddonType, type IDemoAddon } from './types';
 
 export interface IWindowWithTerminal extends Window {
   term: typeof Terminal;
   Terminal: typeof Terminal;
-  AttachAddon?: typeof AttachAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  ClipboardAddon?: typeof ClipboardAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  FitAddon?: typeof FitAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  ImageAddon?: typeof ImageAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  ProgressAddon?: typeof ProgressAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  SearchAddon?: typeof SearchAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  SerializeAddon?: typeof SerializeAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  WebLinksAddon?: typeof WebLinksAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  WebglAddon?: typeof WebglAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  Unicode11Addon?: typeof Unicode11Addon; // eslint-disable-line @typescript-eslint/naming-convention
-  UnicodeGraphemesAddon?: typeof UnicodeGraphemesAddon; // eslint-disable-line @typescript-eslint/naming-convention
-  LigaturesAddon?: typeof LigaturesAddon; // eslint-disable-line @typescript-eslint/naming-convention
+  AttachAddon?: typeof AttachAddon;
+  ClipboardAddon?: typeof ClipboardAddon;
+  FitAddon?: typeof FitAddon;
+  ImageAddon?: typeof ImageAddon;
+  ProgressAddon?: typeof ProgressAddon;
+  SearchAddon?: typeof SearchAddon;
+  SerializeAddon?: typeof SerializeAddon;
+  WebLinksAddon?: typeof WebLinksAddon;
+  WebglAddon?: typeof WebglAddon;
+  Unicode11Addon?: typeof Unicode11Addon;
+  UnicodeGraphemesAddon?: typeof UnicodeGraphemesAddon;
+  LigaturesAddon?: typeof LigaturesAddon;
 }
 declare let window: IWindowWithTerminal;
 
@@ -203,7 +198,7 @@ if (document.location.pathname === '/test') {
   window.WebglAddon = WebglAddon;
 } else {
   const typedTerm = createTerminal();
-  
+
   controlBar = new ControlBar(document.getElementById('sidebar'), document.querySelector('.banner-tabs'), []);
   addonsWindow = controlBar.registerWindow(new AddonsWindow(typedTerm, addons));
   actionElements = {
@@ -217,7 +212,7 @@ if (document.location.pathname === '/test') {
   controlBar.registerWindow(new TestWindow(typedTerm, addons, { disposeRecreateButtonHandler, createNewWindowButtonHandler }));
   controlBar.registerWindow(new VtWindow(typedTerm, addons));
   controlBar.activateDefaultTab();
-  
+
   // TODO: Most of below should be encapsulated within windows
   paddingElement = styleWindow.paddingElement;
 
@@ -226,7 +221,7 @@ if (document.location.pathname === '/test') {
   addons.webgl.instance.onChangeTextureAtlas(e => gpuWindow.setTextureAtlas(e));
   addons.webgl.instance.onAddTextureAtlasCanvas(e => gpuWindow.appendTextureAtlas(e));
   addons.webgl.instance.onRemoveTextureAtlasCanvas(e => gpuWindow.removeTextureAtlas(e));
-  
+
   paddingElement.value = '0';
   addDomListener(paddingElement, 'change', setPadding);
   addDomListener(actionElements.findNext, 'keydown', (e) => {
@@ -576,7 +571,7 @@ function updateTerminalSize(): void {
     };
   }
   if (source instanceof HTMLCanvasElement) {
-    source = source.getContext('2d')?.getImageData(0, 0, source.width, source.height)!;
+    source = source.getContext('2d')!.getImageData(0, 0, source.width, source.height)!;
   }
   const canvas = document.createElement('canvas');
   canvas.width = source.width;
diff --git a/demo/client/components/controlBar.ts b/demo/client/components/controlBar.ts
index 1d695f60..a0424878 100644
--- a/demo/client/components/controlBar.ts
+++ b/demo/client/components/controlBar.ts
@@ -3,10 +3,7 @@
  * @license MIT
  */
 
-/// <reference path="../../typings/xterm.d.ts"/>
-
 import type { Terminal } from '@xterm/xterm';
-import type { AddonCollection } from 'types';
 
 export interface ITabConfig {
   id: string;
@@ -28,7 +25,7 @@ export class ControlBar {
   private _resizeMode: 'none' | 'horizontal' | 'vertical' | 'corner' = 'none';
 
   private readonly _tabContainer: HTMLElement;
-  private readonly _tabs: Map<string, { button: HTMLButtonElement; content: HTMLElement }> = new Map();
+  private readonly _tabs: Map<string, { button: HTMLButtonElement, content: HTMLElement }> = new Map();
   private _activeTabId: string | null = null;
 
   constructor(sidebar: HTMLElement, tabContainer: HTMLElement, tabs: ITabConfig[]) {
@@ -152,7 +149,7 @@ export class ControlBar {
     }
   }
 
-  public registerWindow<T extends IControlWindow>(window: T, options?: { afterId?: string; hidden?: boolean; smallTab?: boolean }): T {
+  public registerWindow<T extends IControlWindow>(window: T, options?: { afterId?: string, hidden?: boolean, smallTab?: boolean }): T {
     // Create button
     const button = document.createElement('button');
     button.id = `${window.id}button`;
diff --git a/demo/client/components/window/addonsWindow.ts b/demo/client/components/window/addonsWindow.ts
index 693fa3ef..b05fd0a4 100644
--- a/demo/client/components/window/addonsWindow.ts
+++ b/demo/client/components/window/addonsWindow.ts
@@ -3,13 +3,10 @@
  * @license MIT
  */
 
-/// <reference path="../../../typings/xterm.d.ts"/>
-
 import type { Terminal } from '@xterm/xterm';
 import { BaseWindow } from './baseWindow';
 import type { IControlWindow } from '../controlBar';
-import type { AddonCollection } from 'types';
-import type { IImageAddonOptions } from '@xterm/addon-image';
+import type { AddonCollection } from '../../types';
 
 export class AddonsWindow extends BaseWindow implements IControlWindow {
   public readonly id = 'addons';
@@ -277,4 +274,4 @@ function htmlSerializeButtonHandler(term: Terminal, addons: AddonCollection): vo
   document.execCommand('copy');
   document.removeEventListener('copy', listener);
   document.getElementById('htmlserialize-output-result').innerText = 'Copied to clipboard';
-}
\ No newline at end of file
+}
diff --git a/demo/client/components/window/baseWindow.ts b/demo/client/components/window/baseWindow.ts
index c541977c..e2667ac8 100644
--- a/demo/client/components/window/baseWindow.ts
+++ b/demo/client/components/window/baseWindow.ts
@@ -3,27 +3,25 @@
  * @license MIT
  */
 
-/// <reference path="../../../typings/xterm.d.ts"/>
-
 import type { AddonCollection } from '../../types';
 import type { IControlWindow } from '../controlBar';
 import type { Terminal } from '@xterm/xterm';
 
 export abstract class BaseWindow implements IControlWindow {
-    protected get _terminal(): Terminal { return this.__terminal; }
+  protected get _terminal(): Terminal { return this._terminalPrivate; }
 
-    constructor(
-        private __terminal: Terminal,
-        protected readonly _addons: AddonCollection,
-    ) {
+  constructor(
+    private _terminalPrivate: Terminal,
+    protected readonly _addons: AddonCollection,
+  ) {
 
-    }
+  }
 
-    setTerminal(terminal: Terminal): void {
-        this.__terminal = terminal;
-    }
+  public setTerminal(terminal: Terminal): void {
+    this._terminalPrivate = terminal;
+  }
 
-    abstract id: string;
-    abstract label: string;
-    abstract build(container: HTMLElement): void;
-}
\ No newline at end of file
+  public abstract id: string;
+  public abstract label: string;
+  public abstract build(container: HTMLElement): void;
+}
diff --git a/demo/client/tsconfig.json b/demo/client/tsconfig.json
index 7676cd37..66a068bc 100644
--- a/demo/client/tsconfig.json
+++ b/demo/client/tsconfig.json
@@ -2,6 +2,7 @@
   "compilerOptions": {
     "module": "commonjs",
     "target": "es2021",
+    "outDir": "../out-demo/client",
     "rootDir": ".",
     "sourceMap": true,
     "baseUrl": ".",
@@ -21,7 +22,7 @@
     }
   },
   "include": [
-    "client.ts",
+    "./**/*",
     "../../typings/xterm.d.ts"
   ]
 }
diff --git a/demo/types.ts b/demo/client/types.ts
similarity index 100%
rename from demo/types.ts
rename to demo/client/types.ts
diff --git a/demo/client/unicodeTable.ts b/demo/client/unicodeTable.ts
index 06111f88..61bba36f 100644
--- a/demo/client/unicodeTable.ts
+++ b/demo/client/unicodeTable.ts
@@ -1,4 +1,7 @@
-/// <reference path="../typings/xterm.d.ts"/>
+/**
+ * Copyright (c) 2025 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
 
 import { Terminal } from '@xterm/xterm';
 
diff --git a/demo/server/tsconfig.json b/demo/server/tsconfig.json
index fcec9d92..2cddc3c9 100644
--- a/demo/server/tsconfig.json
+++ b/demo/server/tsconfig.json
@@ -2,11 +2,12 @@
   "compilerOptions": {
     "module": "commonjs",
     "target": "es2021",
+    "outDir": "../out-demo/server",
     "rootDir": ".",
     "sourceMap": true,
     "esModuleInterop": true
   },
   "include": [
-    "server.ts"
+    "./**/*",
   ]
 }
diff --git a/tsconfig.all.json b/tsconfig.all.json
index 493ec6c9..5983deec 100644
--- a/tsconfig.all.json
+++ b/tsconfig.all.json
@@ -2,6 +2,7 @@
   "files": [],
   "include": [],
   "references": [
+    { "path": "./demo" },
     { "path": "./src/browser" },
     { "path": "./src/headless" },
     { "path": "./test/benchmark" },