Microsoft plans to include APIs for writing advanced instant-messaging apps in the upcoming Windows.Net server, and may build a separate real-time collaboration server to manage them.

Two application program interfaces and a communications update to TCP/IP are scheduled to appear in beta 3 of Windows.Net server, due in November. With them, IT departments and independent software developers could build apps that let workers send instant messages that are encrypted, securely hosted, and allow for more sophisticated types of file transfer than is available today in Microsoft environments, according to Microsoft execs.

By including these APIs and bundling in its SharePoint Team Services software for online project management with Windows, Microsoft hopes to make the operating system more appealing to IT departments.

Microsoft's MSN Messenger and Exchange Instant Messaging employ a common client, and the upcoming Windows XP desktop operating system includes a new Windows Messenger client for voice and video chat.

But a lack of encryption, authentication procedures, and management tools is causing some IT departments to curb use of IM, says Aberdeen Group analyst Dana Gardner. Advanced messaging apps will be valuable to companies with mobile users and customers who need updates on the fly, he says. "Instant messaging is a bright spot in a rather lackluster period in the business."

In addition to developing server-side support for more secure IM apps, Microsoft is developing what it calls a real-time collaboration server that would let IT departments manage IM apps built with Windows Messenger. One Microsoft exec, who spoke on the condition of anonymity, says the server would let IT managers log the exchange of messages and control whether messages can traverse a company's firewall. Microsoft hasn't decided whether to include that software in Windows, or sell it as part of another product.