If you're using a distributed version control system in your software development team (and you really should!) then most possibly you go with Git or Mercurial. But what if you'd really like to use a repository in your project that is on the other system?
Now you can use Git-hg Mirror: it's a super-simple service that automatically keeps a Git and Mercurial (or two Mercurial) repos in sync, even with two-way syncing! Commits pushed to one repo will just magically appear in the other repo. What a time to be alive!
The website is (obviously) built on Orchard - you can see our demo on the last Orchard Steering Committee meeting.