Release of Preview of the Open-Xml-Sdk v3.0

We’re happy to announce the availability of a build of the Open-Xml-Sdk that supports the changes to the file format introduced in Office 2016.  This is version 3.0 of the Open-Xml-Sdk.

The biggest change to the file format is the addition of the ExtendedChartPart, which supports the new chart types, such as Waterfall, Box and Whisker, and Sunburst.

The changes to the Open-Xml-Sdk include the ability to validate the markup in this new part, as well as the ability to use the
strongly-typed object model to access the markup in this part.

This release is a preview – based on feedback, it is possible that there will be further changes to the code.  This release is intended to be 100% backwards compatible with v2.5.  It is my intention to not introduce breaking changes going forward, but if there are any necessary changes, then I’ll keep you informed.

In addition to support for the new markup in Office 2016, I have fixed validation (to a limited extent) where the SDK was reporting
validation errors for markup as written by Office.  My goal is that the markup that Office writes should validate properly using the SDK.

Note: we have not updated the Open-Xml-Sdk Productivity Tool.  That is a project
that I may take on in the future.  Time will tell.  One aspect of the productivity tool that folks may miss is the document reflector, which can generate code that will produce an existing document.  However, with regards to DOCX generation, generating code to generating markup is not the approach that I recommend.  Instead, I recommend the approach of using content controls to pull in data from XML files.  DocumentAssembler is a module in Open-Xml-PowerTools that makes it easy to do this.  For more information, see the DocumentAssembler Developer Center, which contains screen-casts that will help you get started.

If you feel that the document reflector functionality in the Open-Xml-Sdk Productivity Tool is very important to you, please feel free to contact me at eric at, or leave a comment for me on this post.  I would be happy to hear about your scenario and why the document reflector functionality is important to you.

This release is in the Office2016 branch at  To build this release, clone the repo, checkout the Office2016 branch, and use Open-Xml-Sdk.sln to build the library.

Cheers, Eric