SameBoy is an open source Game Boy (DMG) and Game Boy Color (CGB)
emulator, written in portable C. It has a native Cocoa frontend for
macOS, an SDL frontend for other operating systems, and a libretro
core. It also includes a text-based debugger with an expression
evaluator.

Features

Features common to both Cocoa and SDL versions:
  * Supports Game Boy (DMG) and Game Boy Color (CGB) emulation
  * Lets you choose the model you want to emulate regardless of ROM
  * High quality 96KHz audio
  * Battery save support
  * Save states
  * Includes open source DMG and CGB boot ROMs:
      * Complete support for (and documentation of) all game-specific
        palettes in the CGB boot ROM, for accurate emulation of Game
        Boy games on a Game Boy Color
      * Supports manual palette selection with key combinations, with
        4 additional new palettes (A + B + direction)
      * Supports palette selection in a CGB game, forcing it to run in
        'paletted' DMG mode, if ROM allows doing so.
      * Support for games with a non-Nintendo logo in the header
      * No long animation in the DMG boot
  * Advanced text-based debugger with an expression evaluator,
    disassembler, conditional breakpoints, conditional watchpoints,
    backtracing and other features
  * Extremely high accuracy
  * Emulates PCM_12 and PCM_34 registers
  * T-cycle accurate emulation of LCD timing effects, supporting the
    Demotronic trick, Prehistorik Man, GBVideoPlayer and other tech
    demos
  * Real time clock emulation
  * Retina/High DPI display support, allowing a wider range of scaling
    factors without artifacts
  * Optional frame blending (Requires OpenGL 3.2 or later)
  * Several scaling algorithms (Including exclusive algorithms like
    OmniScale and Anti-aliased Scale2x; Requires OpenGL 3.2 or later
    or Metal)