Thanks for noticing! We built badger.com a bit differently from most sites. Our backend is just a JSON api and the frontend uses this API and is implemented entirely in Javascript using an internal library we'll be releasing soon (code name: Hasher).
API Docs - http://badger.github.com/
Frontend Source Code - http://github.com/badger/frontend
Hasher JS Lib - https://github.com/badger/frontend/tree/master/javascripts/l...
So for example, the Javascript behind our DNS manager can be found here -- https://github.com/badger/frontend/blob/master/javascripts/d...