Rocket.Chat - Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.
Embold.io - Peer Code Review
Slack - A messaging app for teams who see through the Earth!
Backlog - A cloud-based project management app for developers and their teams.
Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited
Unfuddle - Unfuddle is a secure, hosted project management solution for software development teams.