mIRC - mIRC: Internet Relay Chat client
Spectrum Chat - A newly open sourced self hosted Slack like alternative for building persistent chat communities
HexChat - HexChat is a fork of XChat with bug fixes and new features.
Just Social - JUST SOCIAL provides all the collaboration tools like enterprise social network, real-time document collaboration
Bidbar - Save and run Terminal commands from the Mac menu bar
Slack - A messaging app for teams who see through the Earth!