MPL section 2.2, and patent grants on derivative works

Mitchell Baker mitchell at
Sat Nov 23 07:10:27 UTC 2002

Brian Behlendorf wrote:

>Apologies if this is retreading old ground, and off-topic since it's not
>about approval of a license, but we're working on the next version of the
>Apache license and are looking at the patent language in various licenses.
Here's how I read it.

>I'm trying to tell if the patent grants by Contributors described in
>section 2.2 apply to derivative works, either published by the same entity
>as the Original Code, or a third party).  My read of 2.2 (IANAL, etc)
>suggest that the patent grant *only* applies to the specific Contributor

>e.g. the Original Code plus the Contribution to which the patent
>applies.  E.g.:
Almost.  The Contributor Version also includes previous Modifications 
made by others. The idea is that a developer makes a patent grant equal 
to the version of code which it created with its Modification.  This is 
broader than making a grant solely to its own Modifications.  We felt 
that allowing an entity to benefit from its use of the entire codebase, 
grant patent license only to its narrow Modifications, and still be able 
to sue all the other developers of the codebase the company used to 
create its Contributor Version was a bad bargain.  A developer who 
contributes more code should not be at a disadvantage vis-à-vis a 
developer who uses that code but makes only small modifications and thus 
more limited  potential patent grants.  Limiting the patent grant to the 
exact Modifications made by the developer would allow the patent 
language to be simpler, since one could dispense with the abstraction of 
the "Contributor Version."  We opted to pay the price of complexity in 
order to minimize the scenarios described above.

>  Each Contributor hereby grants You a world-wide, royalty-free,
>  non-exclusive license [...] under Patent Claims infringed by the making,
>  using, or selling of Modifications made by that Contributor either alone
>  and/or in combination with its Contributor Version (or portions of such
>  combination), to make, use, sell, offer for sale, have made, and/or
>  otherwise dispose of: 1) Modifications made by that Contributor (or
>  portions thereof); and 2) the combination of  Modifications made by that
>  Contributor with its Contributor Version (or portions of such
>  combination).
>What happens to a derivative work of the Contributor Version?  
The scope of the patent grant is not enlarged by subsequent derivative 
works of the Contributor Version.  If the scope was so enlarged, the 
Contributor would have  no idea how broad a set of patent grants it 
would ultimately end up making.

>E.g., the
>developers at merrily commit the patch corresponding to that
>Modification from said Contributor, and then make another commit, and
>another, then make a release.  Given the language in the license, how does
>that patent grant apply to this new work?  This new work is not the
>"Modification alone", nor is it the "Contributor version", nor really "a
>portion of such combination" - it contains the Modification, but even that
>Modification may end up modified at some point.
A Contributor is not making a patent grant for infringements caused by 
code added after the Contributor Version.  Same for combinations -- a 
Contributor is not making a patent grant for infringements caused by 
combinations created after the Contributor Version.  If either of these 
were the case, then the Contributor would have no way of knowing the 
ultimate scope of the patent grants it was making. 

>2.2(d)(3)(i) appears to suggest that "third-party [who's a third party?]
>modifications of Contributor Version" don't get that patent grant; neither
>do those who "combine with other software".  
Section 2.2(d) reflects the extended discussions we had with a set of 
patent lawyers.  I think it's arguable that 2.2(d) is not needed at all, 
it is the negative of 2.2(b).  So "pure" contract drafting might leave 
it out.  But often people want to see what they care about written down, 
not implicit in other language.  2.2(d) is included to provide explicit 
language for those who want to make sure their patent grant is limited.  
So 2.2(d)(3)(i) explicitly says that there is no patent grant for 
infringements caused by code added or combinations created after the 
Contributor Version. 

>Yikes!  That only further
>confuses the situation.  Does putting Mozilla on a CD with some "other
>software" and calling that a product constitute combination, and thus
>lose the patent grants?
One does not lose patent grants that were made in the Contributor 
Version.  Section 2.2(d) is the opposite --if you put Mozilla on a CD 
with other software, you cannot claim that the patent grants made by a 
Contributor now extend to combination you've made. 

>The root question for us (Apache) is, does a contributor grant need to
>explicitly state that a grant of a patent license on a contribution
>applies to derivative works of the resulting "contributor version".  If
>that's the case, some say we need to limit the types of derivative works
>it can apply to, since allowing any derivative work to carry the patent
>grant would mean that anyone with a commercial product who wanted to use
>that patent without paying could do so by pulling the right Apache code
>into their own.  Limiting it to derivative works published by the ASF is
>one option, published under any open source license is another.  But we'd
>really prefer not to invent new language here, so I'm trying to understand
>language like this in existing licenses.
Of course, I'm not giving legal advice.



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