MPL/CDDL patent provisions

Jason White jasonjgw at
Wed Feb 9 06:36:51 UTC 2005

John Cowan writes:
 > I don't think either of those activities, certainly not (a), exceed the
 > limits of the MPL/CDDL patent grants.  As I've said before, a license
 > to use a patentable article is a license to make other articles with
 > it, if it is of the appropriate kind (it wouldn't be much use having a
 > license to use a patented gear if you weren't allowed to make machines
 > incorporating the gear).

I agree. The closest analogy I could find from browsing the relevant
section of an intellectual property textbook, is the distinction
between making a patented article, and repairing one: the former is an
infringement but the latter not. Also, if one applies a counterfactual
(sometimes called a "but for") test of causation to par. (d), then it
can be argued that the modification hasn't caused the infringement as
the original code was infringing already and hence covered by the
grant in par. (b).

 > As for the distinction between (a) and (b), it doesn't seem to me that
 > patent law cares whether the implementation is a modified implementation
 > or a ground-up reimplementation:  either activity infringes absent a
 > license, and neither should infringe when there is a license, as here.

Yes. I would also be somewhat surprised if the language were
originally intended to preclude contributors from reimplementing
patented techniques in covered code in which they were already used
and for which licenses were granted under 2.1 (b) and 2.2 (b). Rather,
I think the purpose of the drafting is to ensure that the patent
license extends only to the patent claims that are actually
implemented in the software, and that contributors don't unwittingly
grant licenses for patents of theirs that others infringe in covered code.
 > Software patents suck, anyhow.
Most definitely. I hope European Union legislators recognize this. I
haven't checked this, but I have been told that Australian law
recognizes software patents, unfortunately. Following the recent trade
liberalization agreement with the U.S., the duration of patents has
been extended to 20 years and other changes have been made to align
the Australian system with that of the U.S.

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