Microsoft is contacting providers of instant messaging software to try to cut licensing deals before it boots the clients from its MSN instant messaging network. Advertisement Microsoft isn't targeting rival IM network operators such as America Online or Yahoo. Rather, the software giant is seeking licensing fees from the makers of clients that use the Microsoft MSN IM network and compete with Microsoft's own MSN Messenger client.

Cerulean Studios, maker of the Trillian IM client, is at the top of Microsoft's hit list. Trillian enables users to consolidate multiple IM accounts in one client and is available in a free version, as well as a $25 Pro version that offers additional features. Trillian has been downloaded more than 10 million times, according to Cerulean Studios. "Running an [IM] network is expensive," says Lisa Gurry, group product manager for MSN at Microsoft. "We can't sustain multiple other-people's businesses, particularly if they charge for certain versions of their software. We're introducing licensing processes for third parties like Trillian."