Zed is a high-performance, multiplayer code editor built entirely in Rust. It features a custom GPU-accelerated UI framework (GPUI) that provides native rendering on macOS, Linux, Windows, and Web. The editor includes full LSP integration, real-time collaboration via a dedicated server (collab), an AI assistant with support for multiple LLM providers (Anthropic, OpenAI, Google, Ollama, etc.), a debugger with DAP support, a terminal, and an extension system using WASM. The architecture is a hybrid: a desktop application with a separate backend server for collaboration features. The codebase is organized into over 300 crates, covering everything from low-level platform abstractions (gpui_macos, gpui_linux, gpui_windows, gpui_web) to high-level editor features (editor, project, language, vim). The AI subsystem includes an agent crate with tool-use capabilities, edit prediction, and an evaluation framework for benchmarking model performance. Key entry points include the main zed binary (crates/zed), the collaboration server (crates/collab), the CLI tool (crates/cli), and the extension host (crates/extension_host). Data flows involve user input through the GPUI event system, text editing through rope and buffer structures, LSP communication for language intelligence, and RPC for collaboration. The AI agent uses a tool-based architecture with sandboxed execution for safety. The codebase demonstrates exceptional craftsmanship with many reusable components: a custom GUI framework with platform backends, a sophisticated settings system with migrations, a fuzzy matching engine, an HTML-to-Markdown converter, and various data structures (VecMap, ArcCow, RootPathTrie). It is actively maintained with frequent commits and a large community.