SimICS
SimICS is an instruction-set simulator and operating system emulator for Sparc V8 (supersparc), capable to run Linux and SunOS. It is a powerful tool for computer architecture research, program debugging, and performance analysis of software systems.
There is an old Linux version and information available here: http://www.sics.se/simics/
The most up to date (and expensive) commercial version is at http://www.virtutech.com/products/simics.html. If you're a student you can get a copy for free.