python and gpl

[Paul Rubin]

Tim Churches <tchur at optushome.com.au> writes:
> >The question is: does shipping a backend which imports a module that
> > links with GPL code make some or all of the library GPL.
> We sought formal legal advice on this issue from a lawyer with
> expertise in open source licensing ...> 
> The answer was that the GPL does not apply to combination of code at
> run-time. Specifically, Section 0., Para 1 (assuming zero-based
> paragraph numbering...) says:> 
> "Activities other than copying, distribution and modification are not
> covered by this License; they are outside its scope. The act of
> running the Program is not restricted,..."

My IANAL amateur reading is that the GPL does in fact apply, at least
in the US.  Running the program is not restricted, but loading the
program from disk to memory before you can run it counts as copying
it, which invokes the license, Computer Associates v. Altai, 982 F.2d
693.  I personally believe that doctrine is insane, but that's what
software companies pushed through the courts in order to make
shrink-wrap EULA's enforceable.  (Otherwise they'd only be enforceable
if you agreed to the terms before the vendor got your money).

> Furthermore, Section 2 para 1 says: "These requirements apply to the
> modified work as a whole. If identifiable sections of that work are
> not derived from the Program, and can be reasonably considered
> independent and separate works in themselves, then this License, and
> its terms, do not apply to those sections when you distribute them
> as separate works. ..."

That means you can run your separate program all by itself without
needing to load the GPL module.

> and Section 2 para 3 says:
> 
> "In addition, mere aggregation of another work not based on the
> Program with the Program (or with a work based on the Program) on a
> volume of a storage or distribution medium does not bring the other
> work under the scope of this License."

That means the two programs have nothing to do with each other.

> On the basis of these clauses, the legal advice to us was that merely
> including "import rpy" and making calls to RPy-wrapped R functions
> does not invoke the provisions of the GPL because these calls only
> relate to run-time linking, which is not covered by the GPL. 

According to the FSF, it doesn't matter whether the linking is static
or dynamic; the GPL applies to both cases.

> Note that the formal advice was specific to Australian law, 

Oh ok, that might be different from US law.  Do you have EULA's there
that are considered enforceable?

> The other, informal advice, was to ignore the FAQs and other opinions
> on the FSF web site regarding intepretation of the GPL - it's only the
> license text which counts.

Ultimately, what really counts are court decisions.  The FSF enforces
the GPL against infringers all the time, and in each case so far, the
infringer has backed down voluntarily because they didn't like their
chances in court.