There's a lot of back and forth in this story about the internal plumbing of instant messaging VoIP services. The issue is which systems are "open." This is an important topic because such systems enable designers to create services in which users of one service can reach subscribers of another.
A Google Talk executive claims its Extensible Messaging and Presence Protocol (XMPP) standard -- also known as Jabber -- is a truly open platform. Jabber, the piece points out, underpins IM VoIP systems from iChat and Trillian.
No story of this type is complete without a bit of sniping, however. Yahoo and Microsoft claim their platforms are open as well. Google Talk counters by claiming that only its system has been approved by the Internet Engineering Task Force (IETF).
Of course we don't know whether all, none or some of the approaches are open. We're not particularly concerned, either.
What we are concerned about is the status of the overall market. The tone of the article suggests something important: that IM VoIP is closing in on systematic interoperability. Now that's news. The story rightly points out that both e-mail and short message service (SMS) took off only after the introduction of ways for systems to trade traffic.
The stakes here are high. Consider where e-mail would be, for instance, if Yahoo and AOL subscribers couldn't send messages to each other. But, once interoperability was established, it was a hit. The same could happen for IM VoIP.