Lifo is a browser-based virtual machine and sandbox environment that emulates a Linux-like OS entirely in JavaScript. It provides a virtual filesystem (VFS), network stack, process management, shell, and an extensive Node.js compatibility layer that allows running real npm packages, dev servers (Vite, Expo, Express), and CLI tools inside the sandbox. The repository is a pnpm monorepo containing multiple packages: `@lifo-sh/core` (kernel, VFS, shell, node-compat), `@lifo-sh/ui` (React components for terminal, file explorer, preview), `lifo-sh` (CLI for daemon/session management), `apps/playground` (interactive web demo), `apps/desktop` (macOS-style web desktop), and many `lifo-pkg-*` command packages (git, ffmpeg, vi, etc.). The architecture is modular: the core kernel is framework-agnostic and can be embedded in Node.js or browser environments, while the UI and CLI are separate consumers. Key data flows involve user input through the shell, command execution against the VFS and network stack, and Node API calls intercepted by the compatibility layer. External dependencies include `acorn`, `browser-metro`, `ws`, and optional `esbuild`. The project is actively maintained with frequent releases, extensive tests, and a clear roadmap for expanding the sandbox capabilities.