Google Talk is out (review at DownloadSquad) and while it doesn’t do all that much to convince users to switch from Yahoo! or AIM, under the covers it is radical for how it works – using an open protocol. XMPP is a messaging/presence protocol that has been around for a long, long time (work was announced way back in January 1999) and has recently been ratified as a standard by the IETF (I think just last year). During that time, numerous instant messaging systems have come along that utilize the protocol, for example Gaim and Gush. The Jabber Software Foundation, has been the main organization that has educated developers as to what it is and be used for, has been an avenue for extensions to be built for it, has promoted it as an alternative to the closed solutions that big three have been promoting, and has helped it thru the standardization process. Yahoo! employee Russell Beattie had this to say about the protocol this morning:

You don’t send individual XML documents per message, instead you open up a socket and start writing one XML document keeping the socket open the entire time, as you need to send more messages, you keep adding XML stanzas to the document. You do this both on the up and down stream. To end the conversation, you simply end your document’s root tag. Now think about this – if you’re really just sending a never-ending XML document as the way to make a conversation, then extending this protocol is drop-dead simple. You just add another namespace and include new tags for that namespace in the document. *Poof* – extensible instant messaging and presence. They’ve got a ton of extension proposals already in the works, including sending forms, multi-user chat, and geolocation. I mean, it’s very cool.

I’m not sure how scalable XMPP is, or why Yahoo! hasn’t switched to it yet, but I’d love to see us put an XMPP gateway at Y! and start letting people access Yahoo! IM via Jabber as well as via our custom client. Our IM client is amazing (with integrated Music, Search, Webcam and Voice), but choice is always better – and then ISVs could start piggybacking on our stuff as well. You still need a Yahoo! ID, so it’s still a win for us… I’m not sure where the decision is kept, but it’d be neat if this turn of events prompted us and MSN and AOL to open up a bit.

Dave Winer has experimented with XMPP in the past and was happy to hear the news.

A while back I read a great book from O’Reilly – (looks like it needs an update) – “Programming Jabber” – that made it trivial to roll your own instant messenger.

Google made a smart choice.