That's the official Vim repository, yes. There are a lot of contributors to Vim, but for consistency with the way Vim patches were handled before it had an SCM, changes are sent as diffs to the mailing-list and manually committed by Bram, rather than just being slurped into the repository with the original author information intact.
I could only find https://code.google.com/p/vim/ , but there are only 3 contributors