Basilisk II is an Open Source 68k Macintosh emulator.

Release notes:

Here’s test6. This one has the minor cleanup of the audio… should sound better for apps that do distinct clips instead of streaming. Major change – I got tired of looking for what was wrong with 4 bit video, so I did a hack – I convert the four bit video into 8 bit and then use the 8 bit code. Works fine. One thing this tells me – the Mac is drawing the four bit correctly, so the problem is with the GU_PSM_T4 handling. I can’t spot the problem… I’ll leave it for another time. This at least makes it where you can read the damn display so initial installs and four bit games should be usable now.

Thanks to for the news.