Custom OS: In-Game Windowed Desktop (UI Toolkit)

# Custom OS

Give your game a real operating system.

Custom OS is a plug-and-play desktop environment for Unity built entirely with UI Toolkit. Add draggable windows, a taskbar, searchable Start Menu, desktop widgets, notifications, and optional UI sounds to create in-game computers, hacking interfaces, simulation UIs, admin panels, and more.

Applications are completely data-driven. Create a new app with an AppDefinition ScriptableObject and a single C# controller class—no prefabs or scene setup required. Everything is built with UXML and USS, making it easy to match your game's style.

## Key Features

• Draggable, resizable windows with minimize, maximize, close, focus management, and cascading

• Taskbar with running apps, searchable Start Menu, and live clock

• Data-driven app system with no per-app prefabs

• Desktop widgets with drag support

• Toast notifications and notification badges

• Optional UI sound bank

• Fully customizable UXML/USS interface

• Standalone GraphElement with Line, Trend, Bar, Pie, and Donut charts

• One-click Setup tool, New App Wizard, Quick Start window, and Fluent icon browser

• Plain C# runtime that can be embedded into any VisualElement

## Included

• Settings app for volume, quality, resolution, FPS, and fullscreen (saved with PlayerPrefs)

• Calculator, Notepad, About, Clock, and System Monitor samples (separate assembly)

## Requirements

• Unity with UI Toolkit support

• No third-party dependencies

• No uGUI required

Asset uses Fluent System Icons under the MIT License; see Third-Party Notices.txt file in package for details.