News

Microsoft Releases Key Specs for Office, Outlook

• By Kathleen Richards
• February 26, 2010

Microsoft has published closely held technical documentation on Office's proprietary protocols and file formats to facilitate data portability and interoperability in multi-platform environments.

Last week, as promised, the company released technical specifications for Outlook's .PST file format, which is used with the software's personal folders. Developers can use the technical documentation and reference materials to access Outlook's e-mail, calendar and contact data from various platforms and programming languages.

As an open specification, the [MS-PST] Outlook Personal Folders File Format Structure Specification is now available on MSDN for public use, which means the documentation -- including schema, Interface Definition Language (IDL) files and code samples -- can be freely copied and distributed as part of an implementation despite Microsoft copyrights, according to the company.

Last October, when the .PST announcement was made as part of the company's ongoing Open Specification efforts, Paul Lorimer, group manager of Office interoperability and author of the Interoperability @ Microsoft blog, explained:

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.

Developers can also use the Messaging API (MAPI) and the Outlook Object Model to access data in .PST files, according to Lorimer, but only on machines with Outlook installed.

It remains unclear whether early [MS-PST] implementations will be covered by Microsoft's Open Specification Promise (OSP), first announced in September 2006. OSP allows developers to use some of Microsoft's proprietary file formats and protocols without licensing fees or fear of patent infringement. For now, it is not part of the official OSP list.

Lorimer explained in his blog post in October:

This documentation is still in its early stages and work is ongoing. 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.

The company also released updated documentation last week on proprietary Office protocols for developers who need to integrate the software with other Microsoft products. Information on the protocol specs, intended to spearhead Office 2010 integration, was first published in July 2009, according to Microsoft. The company started to release public technical documentation on proprietary protocols, languages, standards and formats with the release of Office 2007 Service Pack 2.

The updated Office protocol documents can be viewed here.