gearboy

Gearboy is an open-source Game Boy, Game Boy Color, and Super Game Boy emulator written in C++. It runs on Windows, macOS, Linux, and BSD as a standalone application, and is also available as a libretro core for RetroArch across many additional platforms including Raspberry Pi, Android, iOS, and various consoles. The emulator supports a wide range of cartridge types including MBC1 through MBC7, HuC-1/HuC-3, MMM01, Pocket Camera, TAMA5, and several unlicensed mappers. It offers Game Boy Color and Super Game Boy support, local two-instance link cable emulation, LCD ghosting and dot matrix effects, battery-backed RAM saves, save states with preview and rewind, run-ahead input latency reduction, ZIP-compressed ROMs, boot ROM support, Game Genie and GameShark cheats, and a VGM recorder. A notable feature is the built-in debugger with just-in-time disassembly, CPU and memory breakpoints, code navigation, debug symbols, automatic labels, memory editor, trace logger, IO inspector, and VRAM viewer for tiles, sprites, backgrounds, and palettes. Gearboy also includes an embedded Model Context Protocol (MCP) server that exposes debugging tools to AI assistants such as GitHub Copilot, Claude, and Codex, supporting both STDIO and HTTP transports. Additional Agent Skills are provided for game debugging and ROM hacking workflows. Prebuilt downloads are available for Windows x64/ARM64, macOS Apple Silicon/Intel, and Linux Ubuntu x64/ARM64, with Homebrew, Ubuntu PPA, and Fedora RPM installation options. The project is licensed under GPL-3.0.