Slack

Slack screenshots

Organize your team conversations in open channels or private groups
Main window
Slack 2.5 : Main window

Alternative downloads

Message+
It enables you to send and receive messages from your computer.
1.0.17
FREE
ActiveXperts SMS Messaging Server
It is a messaging framework designed to send, receive and process SMS messages.
5.5.1.4.1111
PinkNotes
Instant messaging application specifically designed for a business environment.
5.20