For more up-to-date versions, do check out emaculation:

http://www.emaculation.com/doku.php/basilisk_ii

The info here is a bit old. Newer versions solve some of the problems mentioned in these comments.

App is pretty Good,
Decent speed, Flexable RAM, I just can't hear the Games, can't play Music,

It works almost great, the thing is that in tiger (10.4.2 ) , when I try to add another volume to mount, the application closes unexpectedly. I hope this is fixed soon

Its a great app , it need some features as sound support , and also when I run in full screen , my mouse is not being detected ( ? )

But I loved it

i like it. it emulates 68k like i had it connected directly to my monitor. and i like being able to start it off with many OSes. But your emulator could realy use sound. That is the only flaw. otherwise Pretty good.

This version is compiled as a Universal Binary, but on my Intel iMac it quits suddenly and unceremoniously part way through booting from my OS 8 CD. I have tried several different ROM files from Performas and Quadras, and consistently get the same poor results. Once-upon-a-time I had a version of Basilisk running on an old PowerPC machine. It was pretty crashy, but at least it ran a bit.