TeamPlay is a web app for team communication that you can run yourself! It is similar to (what I know) about Github's internal 'Team' app, including a free form commenting/message board and a board displaying recent deployments from your team. TeamPlay exposes an API that you can POST to to create these deployments.
Teamplay is written in Python using the Django framework, and uses AngularJS as a front end consumer.
If you like this idea and want to see it happen, fork and submit PRs for new features.