Google Talk is an [XMPP] [http://www.ietf.org/rfc/rfc3920.txt] (aka. Jabber) based Instant Messaging [IM] application that is tied in with Google's e-mail handling service [Google Mail]. [Google] provide a client that can do the usual IM activities (messaging, chat and group chat) and also does voice and video links using their Jingle extension [http://www.jabber.org/jeps/jep-0166.html] to the [XMPP] protocols.

As [XMPP] is an open RFC derived from [Jabber] and [Google] have hooked their servers into the J