Re: GPL 3 and patents question

[Alfred M. Szmidt]

   Let's assume, that GPL 3 is finalized as is today, and that at that
   time the country I live in - Switzerland - still does not allow
   patents on software.

Software patents are still illegal in the majority of European
countries.

   I write some software on my own, and because I live in Switzerland
   I do not care about if what I write is infringing any patents in
   some other countries. I decide to not keep the software for myself
   but rather make it available to others by publishing it.

   Q1: Can I use GPL 3 or would that force me to verify my software is
   encumbered by patents to not violate myself the terms of the GPL 3,
   or be forced to license the patent I would infringe outside of the
   place I live?

I don't think this is related to the GPLv3, or any copyright license
actually.  If you violate a software patent, then you violate it.  A
copyright license cannot give anyone the right to simple violate
patent laws, or any laws.

What a license can do, which the GPLv3 tries to achive, is if a patent
holder uses, modifies, or distributes the program then they cannot sue
you for patent infrigment.

   Q2: If answer to Q1 ist that I cannot use "vanilla" GPL 3, am I
   allowed to add a clause through which I transfer the obligation to
   check for patent infrigements and to apply for a patent licence to
   the user of my software?

That would make the software non-free, since one requires an special
license that allows only a specific subset of people to use the
software.

   Q3: If answer to Q2 ist, that I cannot transfer the obligation to
   check for patents to the user, can I simply license the software
   under GPL 3 with the added clause, that someone may use the
   software only in places which do not know about software patents?

This would also make the software non-free.  The ability to use it for
any purpose, anywhere in the world, is a right that all users must
have.

   Q4: Am I allowed to do such modifications and redistribute the
   software, or am I forced by the provisions of GPL 3 to either make
   sure my modification does not infringe someones patents or license
   myself the patent?

This isn't something related to the GPLv3, it is related to how patent
law works.  So it is your task to check that you are not violating any
patents, and you cannot put the burden on someone else.  This is one
of the major problem with software patents, it is impossible to check
that you are violating single or several patents, they are written in
a very vauge language.

   Q5: If the answer to Q4 is that I am not allowed to do such
   modficiations, but answer to Q2 says that I can transfer the
   obligtion to check for patent infringements and licence the patent
   to the user, am I then allowed to add such a clause to the licence
   of my modified software even though the software I used as base did
   not have such a clause?

Once again, this would make the software non-free.  The user should
not have any obiligation to check anything.

   Q6: If the answer to Q4 is that I am not allowed to do such
   modficiations, but answers to Q3 says that I can limit the places
   where the software can be used, am I then allowed to add such a
   clause to the license of my modified software even though the
   software I used as base did not have such a clause?

Yet again, this would make the software non-free, the right to use,
modify, distribute and study software is a right that _all_ users
_must_ have.

   I appreciate any answers to my questions.

Hopefully my answers will be of help.