Empathy - Apps/Empathy - GNOME Wiki!
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.
Psi-IM - Psi-IM is a messaging program that is designed for the XMPP network.
Facebook Messenger - Facebook Messenger is a faster way to message.
Gajim - Full featured and easy to use Jabber client
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.