MacCentral: Microsoft to lock down MSN Messenger network

Microsoft plans to close off its IM network to third party applications and even older versions of its own software. On Oct. 15, the software maker will start using a different protocol for the purposes of shutting off products and services that have developed without working agreements with Microsoft. This will particularly affect people using applications like Trillian, Imici and Odigo that allow cross-communication among different IM networks or consolidation of multiple accounts.

Microsoft said its reasoning had mostly to do with security concerns, and would not elaborate on what type of agreements or requirements would be imposed on alternative software makers. Marketers have eyed IM networks as possible media venues, but no one has yet struck the magical balance of intrusiveness versus ad effectiveness. The continuing uncertainty created by moves like this one - frequent occurrences in the IM distribution battles among the big players - only serves to make the market more unattractive still.