I don't know if it's still going, but the "Film Gimp" port had color management aspirations back in the day. I used to use GIMP/Linux exclusively until it started to get in my way- it's good for basic edits and has likely evolved since then.
If you're in a class though, this is going to be your single-best time to purchase the Adobe stuff, as the educational discounts are good, and from there on out you'll be in the upgrade path only- if you plan on doing any freelance work in the future, then I'd start saving for the appropriate suite.