Microsoft's new openness and interoperability plan focuses on high volume products such as Windows Vista (including the .NET Framework), Windows Server 2008, SQL Server 2008, Office 2007, Exchange Server 2007, and Office SharePoint Server 2007, as well as future versions of these products.

In a conference call Thursday, Microsoft executives outlined a four point plan that will see the vendor focus on ensuring open connections to its products, promoting data portability, boosting its support for industry standards, and engaging more closely with open source communities.

"We've shared lots of information with partners over the years, enabling developers to write hundreds of thousands of applications for Windows. Today's announcement represents a significant expansion to greater transparency and interoperability," Microsoft CEO Steve Ballmer said on the conference call.

Microsoft will publish on its Website the APIs and communications protocols in its high-volume products that are used by other Microsoft products, and won't require third party developers to buy licenses or pay royalty fees in order to access this information.

Microsoft also plans to develop new APIs for Word, Excel and PowerPoint in Office 2007 to allow developers to plug in additional document formats and to let users to set these formats as their default for saving documents.

Microsoft will clearly delineate protocols that are covered by Microsoft patents, and will offer licenses at reasonable royalty rates and on non-discriminatory terms. The main idea, according to Ballmer, is that Microsoft is opening its intellectual property assets that pertain to interoperability.

"We have valuable intellectual property in our patents and will monetize that from all users of our patented technology. We also have trade secret information that we will continue to protect, expect for trade secrets in the interoperability realm," Ballmer said.

Starting immediately, Microsoft will post some 30,000 pages of documentation for Windows client and server protocols on MSDN, and plans to offer protocol documentation for Office 2007 and other high-volume products in the coming months. Developers could previously access this information only after obtaining a trade secret license through the Microsoft Work Group Server Protocol Program (WSPP) and the Microsoft Communication Protocol Program (MCPP).

The growing importance of easy information sharing, including interoperability across applications and services, is one of the main driving forces behind Microsoft's decision to embrace openness and industry standards, said Ray Ozzie, Microsoft chief software architect.

"Document preservation and portability have become vital concerns for customers. Virtually every system and prodict has become interconnected," Ozzie said on the call. "This reflects our commitment to an open and level playing field in interoperability with these high volume products. "

Microsoft also announced its Open Source Interoperability Initiative, which seeks to build better ties between commercial and community-based open source technologies and Microsoft products. The program will be driven mainly through the use of facilities and events, including labs, plug fests, technical content and opportunities for ongoing cooperative development.