Microsoft opens its software a bit more to the rest of the world? There's more than meets the eye going on.

Microsoft Thursday made another of several broad commitments to more openness, but this time brought concrete actions and promises to the table by, among other things, publishing thousands of pages of protocol documents and offering APIs to third parties so that developers could create products that better interoperate with Microsoft products.

Behind the scenes, a backdrop of antitrust scrutiny, an aggressive push for Microsoft document standards, and continued jostling for competitive positioning against open source and online competitors likely pushed Microsoft toward a newfound fondness for openness and sharing what have heretofore been considered trade secrets.

"When a new type of product or technology is introduced, vendors tend to focus first and foremost on little more than whether their product satisfies an immediate customer need, and in these early stage products, innovation tends to trump interoperability, data portability or any such concerns," Microsoft chief software architect Ray Ozzie said on a conference call announcing the strategy change. Ozzie and other executives point to a changing landscape emerging as Microsoft has matured, one that requires data portability and interoperability.

Microsoft, as its CEO Steve Ballmer noted, is shifting in some ways from being a company that gets added value from developers who create applications that run directly on Microsoft operating systems on a PC to one that gets its added value from applications that connect to and work with an increasingly wide variety of Microsoft software through networks. Meanwhile, Ozzie added, more and more corporate documents have been digitized and need to be stored indefinitely and potentially accessed years down the line, long after their file formats have become obsolete. In that world, openness becomes key for the company's continued success in selling software platforms.

The mainstreaming of Linux and other open source technologies like the Apache Web server is another catalyst for Microsoft to push toward more openness. The actions Microsoft is taking include an agreement not to sue noncommercial open source developers using Microsoft protocols as well as starting several new organizations and efforts tasked with creating open lines of communication between Microsoft and open source communities. Instead of espousing the virtues of Windows everywhere, as Microsoft has in the past, Ozzie admitted Thursday that "heterogeneity is the norm" in most business IT environments.