The Apache 2.0 patent clause says:

Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted.


If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed.

What does that serve to protect? As Apache 2.0 isn't a copyleft license, I can license your code and re-distribute it as a proprietary patent-encumbered product.

Is it to ensure that the original author is giving up his patent rights? Then why not put it outside the license and let the license be GPL2 compatible?


1 Answer 1


Basically, this is designed to protect against using the patent system to circumvent the licence terms.

The first clause means that if I publish anything under this licence, the users are assured that I will not sue them for breach of my patents, as an implicit licence on these is included.

The second clause revokes that right in case someone creates a derived work that is covered by one of their patents, and then proceeds to litigate against their users, effectively adding a fee on the use of open source software.

(non-lawyer interpretation) It would not strictly be necessary to add the second clause, as derived works would also include the implicit grant of all related patent licences. However, in practice end users tend to cave and pay up in this case, and this clause allows upstream patent holders who might have larger coffers to enter the case.

  • So derivatives of Apache licensed code can charge money for the implementation, just not for patent rights? So I can put any EULA I want on my derivative, just not sue someone for violating my patents?
    – user2926
    Oct 7, 2015 at 23:19
  • Indeed. This matters most for contributed code containing patented technologies, and protects the other users. Oct 8, 2015 at 9:55
  • 1
    @uprego, "if you start litigating against your users on patent grounds, we terminate your licence and may start litigating against you on copyright grounds". Sep 9, 2018 at 15:02
  • 4
    1) The patent license is explicit, not implicit. 2) a derived work can be licensed non-APLv2 (right to sublicense is granted). So the second clause is there to discourage say, Microsoft from bundling an existing patented APLv2 library in their own patented product and then suing someone for not obtaining a patent license for the MS product. 3) Patents and copyrights are orthogonal.
    – cowbert
    Oct 6, 2018 at 3:24
  • 1
    @cowbert, true, the second clause is required to cover relicensing. Oct 6, 2018 at 8:18

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