Basilisk II is a fast-as-hell 68k mac emulator.

as for PPC mac emulation, SheepShaver is the best but it's EXTREMELY UNSTABLE and i've only seen ~100mhz performance at best and only runs up to MacOS 9.0.4.

Much like Windows 95/98 3d gaming emulation, Mac also has this missing gap 😀

MESS is great for 68k Mac emulation, almost the entire line of 68k Macs are emulated. A handful of Apple monitors and nubus expansion cards are emulated too.

Some files and info in this thread: http://www.emaculation.com/forum/viewtopic.php?t=6563

The MESS wiki has some mac emulation specific help pages: http://www.mess.org/#documentation

Some MESS MAC WIP topics on Emuversal:
http://forums.bannister.org/ubbthreads.php?ub … at&Number=89558
http://forums.bannister.org/ubbthreads.php?ub … at&Number=81979
http://forums.bannister.org/ubbthreads.php?ub … at&Number=73972

Thanks for all the input so far, Just a general question how far will OS X let me go back and how far will OS 9.2 let me go back!

As far as OS X is concerned, see http://en.wikipedia.org/wiki/Classic_Environment .

As for OS 9, I reckon the best way to find out about an application you want to run is to just go ahead and run it. Keep in mind that, much like PCs, an application that chugs along on a Mac Classic may run much too quickly on a G4 if it is not properly written. And much like PCs, there's probably some extension out there for crippling the CPU to run slower apps.