Just yesterday, I checked out the latest version of Spim (9.0, now with Qt GUI!) from Sourceforge svn. Now I can audit the source, or just hope that attackers just wouldn't bother installing backdoors in such a minority program. I think I'll do the latter.
>"SPIM is a MIPS processor simulator, designed to run assembly language code for this architecture. The program simulates R2000 and R3000 processors, and was written by James R. Larus [...]"
The Qt GUI is nice; however, what I need more is support for acceptance testing of programs generated by the students' compilers. I guess I'll just diff the output of command-line spim like last year.