Yes! A former coworker dug up my old O2 running a 6.5 variant, installed cmake and built BRL-CAD ( http://brlcad.org/ ) with it. Supposedly, it worked quite well (but took a very long time, I believe it was a low end cpu, I want to say 183mhz). Given that I rewrote the build system in 2003 for BRL-CAD to use automake instead of cake, I'm very impressed by cmake.