BGB is described as 'GameBoy and Gameboy Color emulator and debugger for Windows and Wine' and is a Game Emulator in the Gaming Software category. There are three alternatives to BGB for Windows, Linux, Online / Web-based and Self-Hosted solutions. The best alternative is zBoy, which is both free and Open Source. Other great apps like BGB are gnuboy (Free, Open Source) and Gameboy.Live (Free, Open Source).
zBoy is a multi-platform, open-source GameBoy Classic ("DMG") emulator that provides a load/save feature, can perform PCX screenshots and emulates an internal battery for ROMs that were designed to use one.
Gameboy.Live is a Gameboy emulator written in Go (Programming Language) for learning purposes. You can simply play Gameboy games on your desktop. Or, "Cloud Game" in your terminal with a single command: