If you don't what is a repository, it's a storage tool for code supporting version control, branches and many other things.
Gource is a tool to generate repository time lapse videos.
It's more fun than usefull.
It could be a good way to boost team mood with a little geeky restrospective of the accomplished work.
Gource support Git, SVN, CSV, Mercurial ... But everybody use Git right ?