Royalty-free Patent Policies for Open Source?

Lawrence E. Rosen lrosen at
Thu Nov 21 22:39:14 UTC 2002

> I'm aware most Open Source licenses have patent grants.  But 
> in all the 
> cases I've seen, those grants are tied to the specific 
> implementation.  
>   My impression is that the W3C requires that the patents be 
> royalty-free for all possible implementations, not just your own.  
> Right?   Is there anything like that?

Anyone who wants it can have a royalty-free license to patents
containing Essential Claims for implementing the Recommendation.  

The patent license is for Essential Claims only.  It may also be limited
to "implementations of the Recommendation, and to what is required by
the Recommendation."  This so-called field of use limitation was the
subject of much debate at W3C.  Open source representatives were almost
alone in lobbying for a patent license of unlimited scope.

In most cases this field of use limitation will have little practical
effect.  It is unlikely that software patents will have very
wide-ranging applications but, if they do, and if you want to implement
software other than the Recommendation, you'll have to get a separate

The patent grants in most open source licenses are fully compatible with
the W3C patent policy.  The patent grants in the OSL and AFL are *not*
tied to specific implementations and are broader than the W3C patent

/Larry Rosen

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