Shtuff Chat - Free Group / Team chat with persistent history.

Documize - Enterprise-grade wiki and knowledge management platform

Worlize - Worlize is the platform that allows users to communicate with each other in a fun way and play games that are created by the users on this platform.

HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.

Smarsh Instant Messenger - smarshIM Mobile is a free application download that requires a paid account on the smarshIM service...

ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.