Two open source projects to facilitate interoperability with Outlook .pst data files

Microsoft today announced the availability of two new open source projects that complement technical documentation recently released for Microsoft Outlook Personal Folders (.pst). From the press release:

Combined, the documentation and tools advance interoperability with data stored in .pst files, reflecting customer requests for greater access to data stored and shared in digital formats generated by Microsoft Outlook and for enhanced data portability.”

The two open source projects, available on under the Apache 2.0 license are the following:

  • The PST Data Structure View Tool ( is a graphical tool allowing the developers to browse the internal data structures of a PST file. The primary goal of this tool is to assist people who are learning .pst format and help them to better understand the documentation.
  • The PST File Format SDK ( is a cross platform C++ library for reading .pst files that can be incorporated into solutions that run on top of the .pst file format. The capability to write data to .pst files is part of the roadmap will be added to the SDK.

To get more details about how these two projects came to life and understand what type of scenarios they enable, watch this video with Daniel Ko, development manager in the Outlook team.

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If you’re specifically interested about potential scenarios enabled by the SDK, watch this segment of the video:



-- Jean-Christophe Cimetiere, Sr. Technical Evangelist, @openatmicrosoft

Comments (3)

  1. A Citizen says:

    of course, if you want to use something a little more cross-platform, like say…. java, there are libraries appearing like…/java-libpst

  2. JC Cimetiere says:

    @A Citizen:

    The open source SDK is meant to be cross-platform. It's written in C++. That said, for Java developers having Java librairies will help as well. The PST Data Structure View Tool is also very useful to understand the PST specification (which is available under the Open Specification Promise).

  3. Peter says:

    Two years past since this announcement and this open source SDK doesnt even support write access. Why?

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