Heaven is an API that integrates with GitHub's Deployment API. It receives deployment events from GitHub and pushes code to your servers.
Heaven currently supports Capistrano, Fabric, and Heroku deployments. It also has a notification system for broadcasting deployment status events to chat services(e.g. Campfire, Hipchat, SlackHQ, and Flowdock). It can be hosted on Heroku for a few dollars a month.