The key to inter-operability and other features of Gizmo is that it uses both an open-source IM server, Jabber, and an open Internet voice server, called SIPphone. This means anyone can build software for it that connects to the text or voice network. In contrast, Robertson says, AOL, MSN, and Yahoo don't share the specifications for their server or client software -- which is why an AIM user can't chat with someone using MSN Messenger. And while some software, such as Meebo and Trillian, have "reverse engineered" closed network protocols to seemingly combine the major IM networks, Robertson says, they merely supply a unified user interface; there's no true inter-operability.

Beyond voice and text communication over the Internet, other applications have emerged that are a far cry from the traditional image of IM as a computer-to-computer chatting tool. A U.K. company called Trakm8, for example, uses the Jabber protocol and Global Positioning System to send text messages to mobile phones about the location of a car. The system also offers a feature alertings drivers via text messages if their car exceeds the speed limit.

Some investment banks have also adopted Jabber IM, building applications to fit their specific needs. Workers have multiple chat windows open at once, and when certain financial information pops up in one window, it can be routed immediately into spreadsheets containing financial models that, in turn, trigger buying decisions, Saint-Andre says.

Ideally, according to Gizmo's Robertson, people should be able to send instant messages or make an Internet phone call as easily as sending an e-mail message. Someone who uses Microsoft's free web-based Hotmail service, for instance, can transparently send messages to Yahoo Mail or Google's Gmail. This inter-operability dates back to the early days of the Internet, when all e-mail servers were designed to use the same protocol, Saint-Andre says.

IM, however, started out as proprietary software and has stayed that way. Robertson wants to change that with initiatives like Gizmo. "The world I'm trying to create is one in which you have one screen name that works everywhere, very similar to e-mail," he says. "That's not the way IM works today. It's a big mess."