Jitsi is a cross-platform, free and open-source program which supports Instant Messaging (IM), voice and video chat over the Internet. It supports many of the most popular and widely used IM and VoIP protocols, among them SIP (Session Initiated Protocol), Jabber/XMPP (used by Facebook and Google Talk), AIM, ICQ, MSN, and Yahoo! Messenger. It offers additional independent encryption for text chats through the OTR (Off-the-Record) protocol, and voice and video (ZRTP, SRTP) sessions.
Jitsi lets you log into several chat accounts at once. You just need to fill out your username and password for the accounts you already have. If you don’t have any accounts with the providers listed, you can directly create a new account by clicking on one of the “Not registered yet” links. It is as simple as that. Jitsi is a really nice app and as an added bonus, you will have all of your IM contacts in a single window.
Jitsi is an audio/video Internet phone and instant messenger written in Java. It supports some of the most popular instant messaging and telephony protocols such as SIP, Jabber/XMPP (and hence Facebook and Google Talk), AIM, ICQ, MSN, Yahoo! Messenger.