In a lengthy press release issued this morning, Microsoft waxes poetic about what it’s deeming as “broad-reaching changes to its technology and business practices to increase the openness of its products and drive greater interoperability, opportunity and choice for developers, partners, customers and competitors.”

That’s quite a mouthful, but also quite a development for a company that has often been criticized during its 30+ year history for forcing vendor lock-in and engaging in anti-competitive practices. As for some specifics, here are the key, tangible actions Microsoft details in their announcement:

* Ensuring open connections to Microsoft’s high-volume products * Documenting how Microsoft supports industry standards and extensions * Enhancing Office 2007 to provide greater flexibility of document formats * Launching the Open Source Interoperability Initiative * Expanding industry outreach and dialogue.

Looking deeper into the announcement, much of what Microsoft’s doing is providing a more accessible platform for third-party developers to tap into their ecosystem of multi-billion dollar software franchises. For example, the company is launching APIs for Word, Excel, and Powerpoint, and publishing tens of thousands of pieces of documentation to its MSDN site.

Being such a vast company with so many products, it will probably take a while for developers to digest everything Microsoft is announcing and apply it to their own software. However, it’s an incredibly significant announcement, that will have implications for both the desktop and the Web.

The move follows word last month that Microsoft would be hopping on board with DataPortability, a workgroup that aims to make your social networking data (or “social graph”) portable across web services.