wtf is gameboy-emulator?

This project is a Game Boy and Game Boy Color emulator built entirely from scratch in the Kotlin programming language, meaning it recreates the original hardware in software so old game cartridges can run on a modern computer. Alongside the emulator, the author also wrote an original homebrew game called CINZA, a small game made specifically to run on this emulator, so the project covers both sides of the cartridge: the machine and the game. The emulator aims for hardware level accuracy. Its processor emulation advances in the same small steps as the real chip, its graphics system rebuilds the screen the way the original pixel pipeline did, and it includes sound emulation with four channels. It supports several types of Game Boy cartridge memory chips, battery save data, and save states so you can pause and resume exactly where you left off. Beyond the Game Boy, the project has grown into a multi system emulator. It also emulates the NES, matching its processor instruction by instruction against a reference log, and includes support for several NES cartridge types along with games that rely on special interrupt timing tricks. It goes further still with a Super Nintendo emulator, covering both of its processors and enough of its graphics modes to boot real commercial games like Super Mario World, though it notes that games needing exact cycle by cycle timing are not yet supported. All of this accuracy is checked, not just claimed. The project runs 641 automated tests using well known community test programs that check processor instructions, timing, interrupts, and graphics output pixel by pixel, across all three supported systems. There is also a desktop application that ties everything together: a library for organizing your game files by console, adjustable playback speed, fullscreen mode, visual filters, cheat support, and gamepad input. To run it, you need version 21 of the Java Development Kit installed on your computer.