I got redmine installed on my local in-house server last night, took a bit of fumbling (shouldn't have tried to use sqlite as database backend, recent versions are apparently imcompatible with redmine) - and I wasn't familiar with ruby either. Also, the wiki documentation is slightly out-of-date, and it isn't a 100% step-by-step newbie guide.
But with some linux experience and time for googling, it worked out without too much trouble. Haven't put it through much abuse yet, but I added issue-tracking for
fSekrit, found two minor bugs (only in unicode build, which isn't near ready for public prime-time yet) and got redmine configured to auto-close tickets based on commit messages. The whole thing seems pretty slick and well-functioning so far, especially considering it's pre-1.0.