XMPP is an open standard that anybody is free to use, which has led to a handful of different server applications and dozens of client applications being developed. Even Apple’s iChat client natively speaks the XMPP protocol these days. In choosing XMPP as their underlying protocol Google have even been decent enough to allow third party Jabber clients to connect to their servers rather than restricting all users to their own (Windows only) Google Talk client.
One of the nice touches of Jabber is the distributed nature of the servers. There is no need for two users to be using the same server in order for them to chat: the servers are able to route the data around the Jabber network as necessary to get it to its’ destination. This is similar to the way email works, and Jabber IDs actually look exactly like email addresses, taking a usernam@server format.
Unfortunately this is where Google’s openness starts to close up. Google Talk currently doesn’t talk to other Jabber servers. Google Talk users can chat with other Google Talk users, but not directly with any of the many existing Jabber users out there. Here’s what Google has to say about this limitation in their developer document:
We do believe, however, that it is important to balance openness with ensuring that we maintain a safe and reliable service that protects user privacy and blocks spam and other abuses.
This sounds fair enough at first, but consider this: would you use an email service which was guaranteed to be spam free if it meant that you could only send emails to people using the same service?
This is the problem with the majority of instant messaging systems at the moment – AIM users can’t readily chat with MSN users, who can’t readily chat with YIM users, and so on. XMPP was supposed to avoid this problem by being an open standard, allowing for well-defined interoperability between systems.
Of course, like so many of Google’s offerings this is still nominally beta-level software, and so is liable to change. Hopefully one of the first changes they will make will be to open Google Talk up to the wider Jabber world. And if they’re worried about spam and other abuses then here’s an idea: how about only allowing a connection to outside servers if the user has explicitly added the address to their contacts list. That way a malicious third-party won’t be able to initiate a chat unless the user has explicitly said that they’re allowed to.
I have a Jabber account, as do a couple of other people I know. But I know far more people who have Gmail accounts. I’d love to be able to chat to them from my existing Jabber account. So come on Google, open up properly and show the incumbent chat networks how powerful an open standard can be.