✨ What is Lion-OS?

Lion-OS is a genuine desktop environment built from scratch in Python. It has its own boot sequence, a login screen, a window manager with drag / resize / snap-to-edge and corners, desktop icons, an Alt-Tab switcher, a taskbar with a live launcher, a working power menu, and a suite of 15 built-in applications — including a built-in AI assistant that works with local and cloud models.

The v1.1 release ("Refined") added a performance engine (cached window chrome, prerendered wallpaper), window animations, animated theme transitions, and deep feature upgrades across the most-used apps.

The v1.1.1 patch release focuses on memory efficiency: the kernel now reuses full-screen overlay, glow, taskbar and fade surfaces instead of allocating them every frame; app-icon tiles and glass panels are cached; fonts are shared through a global cache instead of being rebuilt per draw call; and the System Monitor's graph no longer allocates a fresh fill surface each frame.

It's designed to be simple to run and genuinely fun to explore:

lionos

That's it. The desktop boots, you log in, and you have a working graphical OS.

🚀 Install

Option 1 — Install from source (recommended)

git clone https://github.com/ram1234598766-dotcom/Lion-OS.git
cd Lion-OS
python -m pip install .
lionos

Option 2 — Install from PyPI

python -m pip install lionos
lionos

Requirements: Python 3.9+. On first run Lion-OS installs nothing extra — Pygame and psutil are dependencies and come automatically.

Option 3 — Run without installing

git clone https://github.com/ram1234598766-dotcom/Lion-OS.git
cd Lion-OS
python -m pip install pygame-ce psutil requests
python -m lionos

🖥 Quick Start

First-time use

1. Run lionos. The OS boots with a progress bar, then shows the login screen.
2. Press Enter to log in as the default user (or set a password in ~/.lionos/config.json).
3. Click the 🦁 Start button (bottom-left) to open the launcher, then search for any app.
4. Double-click a desktop icon to launch an app, or right-click the desktop for a context menu.

Handy shortcuts

📱 Built-in Apps

🧠 AI Assistant

Open AI Assistant, then configure the provider in Settings → AI Assistant:

API keys are read from the environment (OPENAI_API_KEY, DEEPSEEK_API_KEY) or stored in ~/.lionos/config.json. Nothing is hardcoded. For Ollama, run ollama serve locally first.

🎨 Themes

Eight built-in themes with a glassmorphism look, switchable live from Settings. Theme changes animate smoothly between palettes:

• Dark · Light · Ocean · Forest · Violet · Rose · Sunset · Midnight

🚀 Features

• Performance engine — cached window chrome (shadow/body/titlebar), prerendered wallpaper, dirty-flag redraw and a font cache keep the desktop smooth at 60fps.
• Desktop icons — double-click to launch, single-click to select, right-click the desktop for a context menu.
• Window manager — drag, resize, snap to edges and corners, maximize, minimize with open/close/minimize animations, Alt-Tab switcher.
• Power menu — lock, sleep, restart and shutdown from the taskbar, with a fade-out animation.
• Launcher — search-first with category tabs, keyboard grid navigation and a recent-apps row.
• Keyboard-first — Win-key launcher, arrow-key navigation, Alt-Tab window switching.
• Animated theme transitions — switching themes cross-fades every color.
• Shared icon tiles — the same gradient app icons appear in the launcher, taskbar, desktop and About screen.

🧱 Architecture

lionos/
├── cli.py          # `lionos` command-line entry point
├── kernel.py       # desktop env: boot, login, icons, taskbar, launcher, power menu
├── wm.py           # window manager: drag, resize, snap, focus, z-order
├── theme.py        # color themes & blending
├── config.py       # persistent user configuration (~/.lionos/config.json)
├── widgets.py      # UI toolkit: buttons, inputs, sliders, lists, menus
├── ai/             # AI provider backends (Ollama / OpenAI / DeepSeek)
└── apps/           # 15 built-in applications
    ├── base.py     # App base class + registry
    └── ...         # calculator, terminal, paint, notes, etc.

New apps are trivial to add:

from lionos.apps.base import App

class MyApp(App):
    name = "My App"
    icon = "✨"
    def draw(self, surface, rect):
        ...  # draw into the window

# register in lionos/apps/__init__.py

🧪 Tests & CI

Run the automated suite (headless — no display needed):

python -m pip install -e ".[dev]"
pytest

Tests cover boot, login, app registration, app rendering, calculator math (mouse + keyboard), window move/snap/close, corner snapping, Alt-Tab, launcher keyboard nav, desktop icons, theme switching + transitions, window chrome caching, terminal history and notes autosave — plus the headless smoke test.

CI (.github/workflows/ci.yml) runs the full suite on every push and automatically builds a wheel + sdist and attaches them to a GitHub Release on tags. Tag pushes create the GitHub release only; publishing to PyPI is opt-in via a manual workflow run.

📦 Releases

Pre-built wheels are attached to GitHub Releases:

pip install https://github.com/ram1234598766-dotcom/Lion-OS/releases/download/v1.1.1/lionos-1.1.1-py3-none-any.whl

🛠 Development

git clone https://github.com/ram1234598766-dotcom/Lion-OS.git
cd Lion-OS
python -m pip install -e ".[dev]"
pytest                      # run tests
python -m lionos --headless # smoke test
lionos                      # run the desktop

📄 License

MIT © Mrityunjay. See LICENSE.