The Wine project has just started using GIT! This is the second large/huge project using Linus' Torvalds version control system.
What's incredibly neat is that they've put up the entire project history into the repository starting from 1993! Have a look over here at the webinterface.
The Wine people have put up a Wine GIT Wiki to get people started using GIT. For those interested in using GIT, Jeff Garzik's GIT HOWTO makes an interesting read.
In related GIT news: Artem Khodush wrote a webbased GIT browser.