Microsoft announced Wednesday that it is offering to share its Windows source code with its "Most Valuable Professionals" (MVPs) with roots in the Windows arena. So, what's the catch, if any?

First, the newly minted "Most Valuable Professional Source Licensing Program" (MVPSLP) is currently open to a subset of Microsoft's volunteer community army. There are 1,800-plus MVPs out there; 1,200 of these specialize in Windows Server System, Windows and Windows "visual development" (GUI/Internet Explorer) topics. It is these 1,200 who have the option of joining the new program.

MVP shared-source licensees don't get access to all of Windows. According to Jason Matusow, who is manager of Microsoft's shared source program, depending on whether you count Windows binaries as part of the source, licensees have access to between 50 percent and 90 percent of the Windows source code.

The ten percent that is completely off limits includes third-party code which Microsoft includes in Windows but is not authorized to license directly; cryptographic code and "high-value" intellectual property, such as Microsoft's product activation code, Matusow says. Matusow says Microsoft's goal, over time, is to shrink this ten percent to as small a percentage as possible.

In order to license the Windows source, MVPs must sign a master source-code agreement which provides them with a three-year source grant. In order to qualify, MVPs must reside in one of 27 pre-approved countries; be at least 18; and maintain their MVP status. Microsoft does not charge MVPs to license its code, and they are encouraged to use their access to assist the community at large (not just within a single company, as is the case with other Microsoft source licenses) in understanding Windows-related topics.

Once an MVP is granted a shared source license, Microsoft provides him/her with a smart-card access to the MSDN Code Center Premium Web site. Microsoft provides an index to its Windows source base, enabling licensees to search for particular code segments across Windows 2000, Windows XP, Windows Server 2003 and all of the related beta releases and software development kits.

The MVP shared source program is, so far, the smallest of Microsoft's shared source programs. (In addition to MVP, the other communities covered by shared source licenses include academic, OEM, systems integrator, enterprise and government.)

Microsoft announced on Wednesday that it has signed up 27 of the 31 MVPs who helped the company "beta test" the shared source program. Matusow says other interested individuals have expressed interest in signing up as soon as Microsoft can process the paperwork.

Microsoft has been hinting for more than a year that it planned to extend its shared source program to cover MVPs. Indeed, company officials have been reaching out to MVPs for the last couple of years to help the Redmond software vendor improve its community outreach. But in the late 1990s, Microsoft nearly terminated the MVP program. Following MVP outcry, Microsoft reinstated the MVP program in 1999.