The initiative, called The Incubator Club, is said to be a response to the tactics employed by some major software vendors against firms and organisations who consider using Linux.
According to Eddie Bleasdale of Netproject, an IT consultancy firm that runs The Incubator Club, Microsoft has repeatedly tried to stop potential Linux migrations -- sometimes with notable success.
"Whenever we've gone public about a client moving to Linux, Microsoft has come in and offered remarkable incentives for them to stay as they are," Bleasdale told the Open Source in Local Government conference in London on Tuesday.
The Incubator Club, he said, is a forum where IT directors can exchange views and experiences related to open-source migrations, and one where problems can be identified and addressed.
Companies joining The Incubator Club will be able to test a pilot version of Netproject's Linux desktop, called the Secure Open Desktop Architecture. SODA uses smart cards that plug into stateless PCs running Linux, allowing users to hotdesk between computers and claims to avoid the security problems inherent in a Windows-based environment.
Bleasdale emphasised that in The Incubator Club, confidentiality is paramount. "The number one rule is that you don't talk about anyone else being a member," Bleasdale told the conference.
Speaking to ZDNet UK, Bleasdale declined to say how many members have already joined the club, which costs from £15,000 -- depending on company revenue -- to join.
Microsoft scored something of a win over Netproject in January, in the London borough of Newham. Newham Borough Council had been trialling Netproject's Linux product, but eventually abandoned plans to move to open source in favour of a new deal with Microsoft instead.
Bleasdale, who expressed his admiration for the poker skills of Newham Borough Council's head of IT, says that Microsoft was forced to offer an "unbelievable deal" in order to keep Newham onside.
Given Microsoft's long-standing fear of the effect that open source could have on its dominance of the desktop market, some in the industry believe that government bodies and private firms could find that "doing a Newham" could dramatically cut their IT costs without involving a migration away from Windows.
Others, though, claim that software vendors are more determined than ever to lock customers into using their products, and that companies who don't start moving to open source soon might never be able to do so.
Following its success in Newham, Microsoft launched an advertising campaign in which it claimed that Windows was cheaper than Linux -- an echo of a controversial piece of research from analyst firm Gartner, which claimed that migrating desktops from Windows to Linux would often not save money.