We used it for a Software Engineering project in college just this last semester. We were instructed that (as a fake client) that they needed a way to do internal reviews through a separate agency (all fake). Of course, we initially only used it to solve that issue in our fake software design, but the flexibility and ease of use caused us to replace the internal Comp Sci repository system with it. We're more than pleased with it. Both the faculty and students so far seem to enjoy it a lot more than the previous (decrepit) SVN system.

The chair of the department loves Git, but couldn't find a decent (open source) web solution that could be hosted on our systems (as in not Github). Gitlab is an amazing solution.