What is gb?

Leiksveinn GameBoy is an emulator that lets you play original Game Boy and Game Boy Color games on a computer or in a web browser. It is written in C and built to be readable and easy to modify, favoring straightforward code over layers of abstraction, with a companion architecture document that explains how the pieces fit together. Under the hood, it reimplements the original hardware's central processor, its pixel by pixel graphics processing, and its full four channel sound system, and the project reports passing a wide range of standard accuracy test suites used by the emulation community to validate correctness. It also supports Game Boy Color features, including color palettes and the higher speed mode those games can use, and it can be forced to run in a specific hardware mode if needed. A long list of cartridge types are supported as well, covering the different memory bank switching chips real Game Boy cartridges used, including ones with a built in real time clock for keeping track of in game time even when the game is off. Beyond emulating the console itself, it supports save files and full save states, screenshots, fast forwarding through gameplay, an on screen frames per second display, and even the physical Game Boy Printer accessory, with printed images saved as bitmap files. Two people can also play together locally using a simulated link cable connection, split across two windows. The emulator runs natively on a computer using SDL3, but it can also be compiled into WebAssembly to run directly inside a web browser, including as an installable app that keeps working offline, complete with on screen touch controls for playing on a phone. Importantly, this project does not include any actual Nintendo code or game files. You must supply your own game ROMs, which are never included in the repository. The emulator's own code is released under the MIT license, one of the most permissive open source licenses available.