Some questions about GPL
jbn at forestfield.org
Wed Jan 19 13:53:12 EST 2005
I'm addressing these points here because the GPL is a CC-recommended license.
For a thorough discussion of the issues you ask about, please consult:
- the GPL itself
- the GNU GPL FAQ http://www.gnu.org/copyleft/gpl-faq.html
- the GNU GPL quiz http://www.gnu.org/cgi-bin/license-quiz.cgi
- the Usenet group gnu.misc.discuss (the GPL is often discussed there)
- the Free Software Foundation (they wrote the GPL)
Daniel Olmedilla wrote:
> I know that GPL is free distribution license where if a piece of software
> has this license any modification of that software must include GPL as well.
> I am interested in knowing if this applies also to applications that use
> that software.
Simply running the software is not a power regulated by copyright law,
according to the FSF (see the bottom of their explanation on why the Apple
Public Source Licenses v1.x were not free software licenses --
http://www.gnu.org/philosophy/historical-apsl.html). More specifically (and
accordingly) the GPL v2 does not place conditions on running the program (from
the last paragraph of section 0):
"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, and the output from the Program is covered only if its contents
constitute a work based on the Program (independent of having been made by
running the Program). Whether that is true depends on what the Program does."
> My situation is that I am considering to use software under GPL from other
> applications and developments I make and give the whole to clients. Of
> course, the software under GPL would be released for free to the clients and
> only charge for installation (is this also possible?) but I would charge
> for the new developments (which has no lines in common with the GPL
> software). Is that possible?
You can charge for distributing the GPL-covered software (no matter who
holds the copyright to the programs). You can provide services for the
software for a fee (examples include system administration, programming,
providing explanations for how things work). There are limits on how much you
can charge to supply the source code for any GPL-covered binaries you
distribute (GPL section 3b).
> I know that GNU allows you to sell any product that uses the software under
> the GNU license (e.g. Apache Axis), right? However, I am not sure if it is
> possible to do something similar with GPL.
GNU is an operating system. What concerns you is what the GPL allows when you
don't hold the copyright to the covered program. If you are distributing a
program for which you hold the copyright, the conditions of the GPL don't apply
More information about the cc-licenses