Tuesday, December 18, 2007

GPL and sublicensing

Story here, repeated almost verbatim here

A common criticism of the MS OOXML specification is that the patent promise is insufficient to allow an open source implementation without problems, and this story makes a specific claim about the patent license that we can examine:

"What Microsoft intends to do with its OSP is to forbid sublicensability, which is one of the cornerstone for distributing GPL code."

Legally, there are really two aspects to this: first, is sublicensing a corner stone for distributing GPL code (covered by copyrights), and second, does that apply to patent rights (rather than copyrights)? It's important to address both those aspects, since either could be true and would affect distribution in different ways.

First, the copyrights themselves. The GPLv2 doesn't address copyright sublicenses explicitly, but does say that "the recipient automatically receives a license from the original licensor" (section 6) which isn't a sublicense. GPLv3 is explicit, though: "Sublicensing is not allowed; section 10 makes it unnecessary." (section 2, last para).

Now addressing patents, the position GPLv2 takes on patent licenses is "a patent license [must] permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you" (my edit, the GPL states that in the inverse, section 7). It doesn't require the ability to sublicense, or request it.

GPLv3's section 11 (Patents) is considerably more complex than the v2 counterpart, but in essence requires contributors to grant a "non-exclusive, worldwide, royalty-free patent license". It doesn't ask for the ability to sublicense, and it's difficult to see why you'd need one given the initial license granted by contributors.


smaffulli said...

I'm not sure I understand your post. To me it seems that you are confirming that the OOXML patent pledge is insufficient to cover GPLv2 and GPLv3 covered software.
Do I get it right?

Fact-Finder said...

It's not really about the patent promise at all; the claim was that sublicensability is required for GPL'd works. Given GPLv3 specifically disallows sublicensing, and GPLv2 doesn't seem to need it, the claim that sublicensing is necessary is a bit dubious to me.

Whether or not the patent promise is sufficient in general is a different matter - the sublicensing is only one issue raised, and it's not really possible to say whether the other issues are problems or not. There are people with legal experience/knowledge whose opinion goes both ways, so it seems the best you can say about the promise is that it's not clear.