# trekawek/coffee-gb

Gameboy emulator in Java and Kotlin.

Repository: https://github.com/trekawek/coffee-gb
Canonical: https://ross.abutalabs.com/products/coffee-gb
Language: Java
License: MIT
License Family: permissive
Topics: gameboy-emulator, gameboy, emulator, z80
Last push: 2026-09-02T21:13:29+00:00

## Health v2 (maintenance only)
Score: 100/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 100, longevity 100
- inputs: {"age_days": 3526, "days_push": 0, "days_rel": 2, "gap_med": 2, "n_releases_24m": 30}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1168, forks 83 (observed 2026-09-03T02:15:19.944776+00:00)

## What it is
Coffee GB is a highly compatible Game Boy and Game Boy Color emulator for the desktop, written in Java and Kotlin. It includes a reusable emulation core plus a full desktop application with save states, rewind, rollback netplay, and broad cartridge and accessory support.

## Use cases
- play gameboy games on my computer
- emulate game boy color roms on desktop
- run homebrew gameboy demos and diagnostic roms
- play link-cable gameboy games online with netplay
- use save states and rewind while playing gameboy games
- apply game genie and gameshark cheats to gameboy games
- test gameboy homebrew compatibility

## When to choose
- you want a highly accurate GB/GBC emulator with strong compatibility including unusual cartridges and accessories
- you need save states, rewind, screenshots, and battery saves
- you want rollback netplay for link-cable games
- you prefer a JVM-based emulator or want to reuse the Java emulation core

## When to avoid
- you need to emulate other consoles or handhelds beyond Game Boy and Game Boy Color
- you need a mobile or web-based emulator
- you want a libretro core rather than a standalone desktop application
- you need ROM files included - they are not provided

## Facets
- artifact type: application
- maturity: active
- function: game-engine, simulation, gui
- domain: gaming-tools, cross-platform, developer-tools
- platform: cross-platform, jvm, windows
- tags: gameboy-emulator, gameboy-color, emulation-core, kotlin, java, save-states, rewind, netplay, super-game-boy, cheats, desktop, macos, linux

## Member repositories
- trekawek/coffee-gb (main) score 100

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:19.944776+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:29:18.849830+00:00, confidence not recorded.
  - readme: https://github.com/trekawek/coffee-gb (fetched 2026-09-03T02:15:19.944776+00:00, sha a6468a131527)
- Data as of 2026-08-30T08:39:29.467469+00:00.