Lorimer said that "In order to facilitate interoperability and enable customers and vendors to access the data in .pst files on a variety of platforms, we will be releasing documentation for the .pst file format. This will allow developers to read, create, and interoperate with the data in .pst files in server and client scenarios using the programming language and platform of their choice. The technical documentation will detail how the data is stored, along with guidance for accessing that data from other software applications. It also will highlight the structure of the .pst file, provide details like how to navigate the folder hierarchy, and explain how to access the individual data objects and properties"
He also admitted that that the documentation is still in its early stages and work is ongoing. Going on to say "We are engaging directly with industry experts and interested customers to gather feedback on the quality of the technical documentation to ensure that it is clear and useful. When it is complete, it will be released under our Open Specification Promise, which will allow anyone to implement the .pst file format on any platform and in any tool, without concerns about patents, and without the need to contact Microsoft in any way."
This initiative is part of Microsoft's Interoperability Principles, which they announced in early 2008. As part of this initiative Microsoft has committed product features, documented formats, and implementation of standards that allow interoperability. The move to open up the portability of data in .pst files is another step in putting these principles in action.
Lorimer also said that "Over the past year, Microsoft Office has taken several steps toward increasing openness and documenting interoperability guidelines, offering customers a choice of file formats and embracing a comprehensive approach that includes transparency into our engineering methods, collaboration with industry stakeholders, and shared stewardship of industry standards"
This is a great move by Microsoft!