From Richard Bannister:
TGEmu/MacOS is a PC Engine emulator for the Macintosh.
TGEmu features reasonably good compatibility with PC Engine HuCards. While this release does not support CD-ROM based software, this will be included in a future release. Sound emulation is supported. Sprite priority emulation is supported as an option for the games that need it. Also, the emulator can use Gzip compressed ROMs transparently.