Instant Messaging

A traditional chat with group videoconferencing

Unofficial desktop client for Facebook chat

Chat with your Yahoo and MSN Messenger contacts

Talk to all of your MSN contact even with your Mac

Cooperative whiteboard and voice communication through Jabber

A simple Jabber-based IM client

A single program for all your IM accounts

Chat with friends on this multiplatform messaging client

Just like Whatsapp but from your Mac's desktop

iOS's iMessage now also on Mac OS

Multiplatform IM client