Just like Whatsapp but from your Mac's desktop
Unofficial desktop client for Facebook chat
A traditional chat with group videoconferencing
AOL's instant messaging program
Chat with friends on this multiplatform messaging client
iOS's iMessage now also on Mac OS
An IM combo born of Mozilla and Pidgin
A Multiprotocol Instant Messenger client
A single program for all your IM accounts
Multiplatform IM client
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
Add a bunch of improvements to iChat
Open Source alternative to chat with MSN contacts
A simple Jabber-based IM client
Share files and chat with friends safely