@@ -3836,14 +3836,26 @@ GPLv3~\S11\P3 makes this clear by defining ``patent
license,'' for purposes of the subsequent three paragraphs, as ``any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement)''
The definition does not include patent licenses that arise by
implication or operation of law, because the third through fifth paragraphs
of section 11 are specifically concerned with explicit promises that purport
to be legally enforceable. The final paragraph of section 11 explicitly
sue for patent infringement)''.
``Express'', as used GPLv3~\S11\P3, is a term often used in legal writing as
an antonym to ``implied''. Thus, GPLv3's definition of ``patent license''
does not include those patent licenses which arise by
implication or operation of law\footnote{FIXME: explain this}.
Instead, GPLv3~\S11\P3--5 are specifically concerned with explicit promises
that are purportedly legally enforceable.
Nevertheless, unlike traditional commercial patent licensing
agreements\footnote{FIXME: note such a clause is rare, if not unique.},
rather than confining the patent license grant to some narrow set of such
express situations, GPLv3 preserves the
\hyperref[gpl-implied-patent-grant]{existing implied patent licensing structure}
found in GPLv2. Specifically, the final paragraph of GPLv3~\S11 explicitly
preserves the availability of patent licenses arising by implication or
operation of law.
operation of law. GPLv3~\S11's final paragraph dissuades potential
misinterpretation disparity between GPLv2 and GPLv3 --- namely, that some
might argue an explicit patent license would otherwise cause any implied
patent license to evaporate.
GPLv3~\S11\P5 is commonly called GPLv3's downstream shielding provision. It
responds particularly to the problem of exclusive deals between patent