Users will be able to customise profiles and feeds, decide who gets to see what information about them and receive status notifications of colleagues' whereabouts and the projects on which they are working.
The system is currently used daily by about 700 Microsoft employees, the company said, and is also under test at unnamed Microsoft customers.
Microsoft and third-party software developers see SharePoint as a natural basis for developing corporate web 2.0 applications.
Microsoft is also backing commercial social networking following a US$240 million stake in Facebook dating from October 2007.