[Asterisk-Users] Help with GPL license of Asterisk

[Jan Rychter]

>>>>> "Mark" == Mark Spencer <markster at digium.com> writes:
[...]
 Mark> No problem, it's easy to get confused :) I would, however, take
 Mark> issue with the GPL being "evil".  It's not my *ideal* license,
 Mark> but it certainly is good enough.

Just for the reference, while we're at it. GPL does have an issue, which
can cause problems to some people or companies. It is often overlooked,
because the "open source" issues seem much more controversial.

Having worked with GPL software quite a bit, also in the commercial
world, and having gotten some legal advice, I believe that the
"anti-patent" clauses in the GPL and LGPL are quite possibly the biggest
problem preventing the use of GPL'd software by commercial entities,
much bigger than the "pass on the source and the rights" requirement.

An excerpt from the GPL:

     7. If, as a consequence of a court judgment or allegation of patent
   infringement or for any other reason (not limited to patent issues),
   conditions are imposed on you (whether by court order, agreement or
   otherwise) that contradict the conditions of this License, they do not
   excuse you from the conditions of this License.  If you cannot
   distribute so as to satisfy simultaneously your obligations under this
   License and any other pertinent obligations, then as a consequence you
   may not distribute the Program at all.  For example, if a patent
   license would not permit royalty-free redistribution of the Program by
   all those who receive copies directly or indirectly through you, then
   the only way you could satisfy both it and this License would be to
   refrain entirely from distribution of the Program.
 [...]
     8. If the distribution and/or use of the Program is restricted in
   certain countries either by patents or by copyrighted interfaces, the
   original copyright holder who places the Program under this License
   may add an explicit geographical distribution limitation excluding
   those countries, so that distribution is permitted only in or among
   countries not thus excluded.  In such case, this License incorporates
   the limitation as if written in the body of this License.

As I understand it (and as my legal counsel advises me) this effectively
means that if I distribute GPL/LGPL code, I have to make sure that its
distribution and re-distribution is not restricted by patents (or other
restrictions).

If the code in question contains parts which some patents lay claim to,
restricting distribution, then I must not distribute the code at
all. Furthermore, by distributing the code I breach the GPL and expose
myself to legal threat of a lawsuit from the FSF.

It is needless to mention that it is impossible to me to verify that no
patents (worldwide!) lay claim to the code I'm distributing and impose
restrictions upon its distribution. Sooner or later I'm going to find
out that I do not comply with the GPL, because I distribute GPLd code
even though there are patent restrictions that apply to it.

An example of a particularly clear case of this problem is the XviD code
(http://www.xvid.org/), which is GPL-licensed. It seems to me that the
authors (copyright holders, to be precise) may distribute the software
under any license they choose, but nobody else is allowed to
re-distribute it, because they would be violating section 7 of the GPL,
as the MPEG-4 compression is (in some countries) covered by patents
requiring royalties to be paid.

This is an issue which is very often overlooked in the hot GPL
debates. However, in the commercial world, it is possibly the most
important one.

Conclusion (IMHO of course): if you have the choice, use a license that
is OSI-compliant but does not have the "anti-patent" clause. Or has it
phrased differently.

--J.