No license needed to use the Office Open XML formats

I still get folks asking me questions about the licensing of the Open XML formats from time to time, and it seems there is a lot of misinformation out there. It's actually been well over 7 months since we made the move away from licensing the formats and instead just provided a general commitment to not enforce any IP behind the formats. The legal term for this new commitment is CNS (covenant not to sue). This allows anyone to develop against our formats without having to worry about patents, and this it's irrevocable (meaning it can't be changed in the future).

The CNS is available up here ( Recently we took an additional step to help people who don't want to deal with parsing legal documents, and actually asked an outside law firm (Baker & McKenzie) to do a study for us on both the standardization as well as the CNS. I think any of you folks who've been frightened by some of the FUD that has been spread about the Ecma Office Open XML formats should take a look: (Link)

Some good takeaways I wanted to call out were:

  • "In this case, the CNS is a unilateral statement to the world about Microsoft's future behaviour towards the enforcement of its patent rights contained in the Schema. While the covenant governs Microsoft's future behavior, it is retrospective in effect, applying to any past uses of the Schema that may have been in actual or potential breach of the terms of the preceding Patent License."


  • "By stating that the covenant is 'irrevocable', Microsoft has protected users against a change in company policy at any point in the future."


  • "The CNS is therefore considerably more favourable to a person relying on it, than any form of patent licence because it does not impose positive restrictions on beneficiaries' activities as a condition of relying on it."


  • "Microsoft's CNS is similar to a covenant issues by Sun Microsystems Inc., in September 2005, in respect of any patents that it hold in respect of the Open Document Format ('ODF') for Office Applications (OpenDocument) v1.0 Specification ('Sun's Covenant')."


  • "The CNS does not affect users' rights to create their own applications using the Schema specifications. For example, there are no restrictions in the CNS that would prohibit third parties from incorporating the standard into applications they create and distribute in source code form, or for other hardware or operating-system platforms. Such applications, developed by third parties, will generally be subject to separate legal agreements, licences and covenants that the developers of those applications may impose, such as Sun's Covenant in respect of ODF. "


  • "Any such restrictions will be determined by the development and licensing practices of the third-party developer, not by Microsoft; and this will be as true for applications developed under the ODF standard as it is for applications incorporating the Open XML Schema standard."

Have a great weekend everyone!


Comments (4)

  1. hAl says:

    Thanks for clearing that up Brian.

    I would suggest Microsoft puts up a simularly comprehensible short statement on it’s website when the format is ready.

  2. Doug Mahugh says:

    Baker & McKenzie’s London office has pubished a paper on the Open XML formats and the Ecma standardization…

  3. Slightly off topic, but it occured to me that Microsoft could really help the .docx standard by adding support for it in the ASP.NET toolbox components.

    For instance, a free to use docx viewer component would be amazing to allow people to use Word to create a document just the way they like it, and then upload the document AS IS to the corporate website. An ASP.NET page could load the document in the DOCX viewer component, and suddenly everyone can create content for the web in an environment they know.

    The nice thing about ASP.NET is that it generates HTML. This approach would also provide a client platform-free viewer for Microsoft’s XML standard. Government saying they want to expose their internal information to the public in a simple way, would need to look at Microsoft’s DOCX is the easiest way to do so. I realise that fidelity in HTML cannot be 100%, but XAML will remedy that in the future. In later versions of the standard ASP.NET block, Microsoft can provide intra-component checking for the available platform (XAML or not), and adjust accordingly. The whole world would dynamically change over to using XAML simply by recompiling their ASP.NET sites with the lastest version of Visual Studio.

    Putting just 1 internal Microsoft person on such a project would make a lot of difference to the whole world. It seems to me like one of the best ways to create a free Word viewer (you might hear people asking for a PPTX viewer next :-)).


  4. For those of you not only reading my blog, but also the other content provided by the Info Support blog

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