NEW YORK (Fortune) -- Aiming to take advantage of its already-impressive momentum, San Francisco's Linden Lab, developer of the Second Life virtual online world, will announce Monday that it is taking the first major step toward opening up its software for the contributions of any interested programmer.
The company will immediately release open source versions of its client software for Windows, Mac OS, and Linux. In order to enter and move around the Second Life service, users must download and run this software on their computer desktop. But now, says Linden CEO Philip Rosedale, independent programmers will be able to "modify it, fire it up and sign on with it." The company gave Fortune exclusive access to executives in advance of the change.