Rocket.Chat - Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.
Xmind - Xmind is a brainstorming and mind mapping application.
Slack - A messaging app for teams who see through the Earth!
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited
FeatureMap - FeatureMap story mapping, simple and effective realtime collaboration and collective intelligence tool.