Source: snapvoip.blogspot.com

I was at news site today reading about VOIP/IM by Carl Weinschenk. He brings out ideas and thoughts brought about by an article on Light Reading by Mark Sullivan, Google: Resistance Is Futile…
Both the articles tells us how diverse is the VOIP/IM sphere right now is. Just like the early early early email. When email from one client could not go to another email client nor read it even if it was received.
Google is going about this in another angle, with google talk.
For Internet-based VOIP, Google uses XMPP, based on Jabber protocol and setting it as the standard. Г‚We said we were going to use an open standard from day one,Г‚ Google Talk product manager Mike Jazayeri says. Other IM clients such as Apple’s iChat and Cerulean Studios’ Trillian also are underpinned by the XMPP standard.
Google Talk can now jabber away with users of such services as EarthLink Inc. , Gizmo Project , NetEase.com Inc. Chikka Asia Inc. , and MediaRing Ltd. , as well as with numerous other Jabber-based clients homegrown by ISPs, universities, and corporations.
When email federation happened, usage of email exploded. Usage of wireless text messaging also grew exponentially after the wireless service providers adopted the common SMS standard enabling, for example, a Cingular Wireless LLC customer to send messages to a Sprint Wireless account.
Read both the article to get a good idea of where VOIP/IM is heading!

Google is planning to go places with googletalk too! see the this googletalk blog post;
Now anyone can Talk
Google Talk is now open to everyone! Until now, users needed a Gmail account to use Google Talk. Now, anyone can use the service by creating a Google Account.