Bernie ][ the Rescue
An Apple IIgs emulator by F.E. Systems Emulation Technologies. Runs on PowerMacs only.
Catakig
An Apple II, II+, and IIe emulator. "Fat" application, capable of running on 68K or PowerPC Macs.
Emulation.net
Dedicated to emulation on the Mac OS. The latest emulator news and downloads.
Mac Emu
Allow Macintosh computers to run old games and applications. Includes message boards, chat, benchmarks, and tools.
Mac EmuScene
Mac EmuScene is a major resource for Macintosh emulation. It has downloads, interviews, articles, and of course, up to date news.
MacWise
Commercial Macintosh terminal emulation software for Wyse 50,60,360, Viewpoint, DEC, Televideo, and Esprit.
NoSTalgia & PowerST
Two AtariST emulators by Gérin Philippe for the Macintosh. Requires Mac OS 8, 9, or OS X.
Power64
A Commodore64 emulator for the Macintosh.
Richard Bannister's Macintosh Emulation Softw
Lots of emulators of computers and console systems that run on the Macintosh.
VirtualPC
A PC emulator for Mac from Microsoft. Allows DOS, Windows, and Linux operating systems to be installed within the emulator environment.