Re: licensing confusion
Marek Habersack wrote:
On Thu, Mar 04, 2004 at 02:45:12PM -0300, Humberto Massa scribbled:
Do Cc: me on the replies, thank you
[snip]
It's simple - how is it possible that most licenses used by free
software are incompatible [1] with GPL and yet debian mixes them in many projects
it distributes (like mozilla, php, apache to name the most prominent ones).
The GPL-compatibitily problem only arises in the case you *link*
Like in the case of mozilla linking against libfreetype6?
ok, let me see. Mozilla is triple-licensed, so it is *the* bad example.
*But* AFAIK the mozilla licensing is triple exactly to make it
GPL-compatible and, if freetype is L?GPL, there is no link-incompatibility.
something with something else. _Any_ DFSG-free license permits you to: bundle and distribute differently licensed things together, _as long as_ they are not derived works. GPL further defines linkage as deriving for the purpose of licensing.
So that would make mozilla in conflict with GPL since some files in
mozilla are NPL, some MPL and some GPL. That makes _parts_ of mozille code
non-compatible with freetype6 which is distributed under GPL/FTL with
FTL being incompatible with GPL. So, what in this case?
when we say "Mozilla is distributed under the MPL, NPL, and GPL", means
*you*, as the receiver can ... insert doing stuff you normally could not
do under regular copyright law ... if and only if you concur to abide
(and abide) to the terms of *at least one* of them. So, if you want to
link them together (mozilla and freetype), you can license mozilla as
GPL, freetype as GPL, and there you go, no incompatibilty.
What are the rules to freely (as in freedom) use the other licenses whichare incompatible with GPL and to remain compatible with GPL without being forced to use it in your own projects which you don't want to license under GPL/LGPL?
My rules of thumb are:
1. in doubt, GPL it.
I'd rather public-domain it, really... precisely to avoid having to
wonder whether it is compatible with openssl, apache, php, nspr/nss and
whatever else...
(a) in some jurisdictions, you can't PD something without going to great
lenghts (registering in a notary _there_, paying a fee, etc)
(b) if you want maximum compatibility, 2-clause BSD is ideal. (because
any derived work can further restrain distribution)
2. if it is a library and I want proprietary software to use it, I use GPL or the 2-clause BSD.
3. _do not_ invent a new license.
I'm not going to, just trying to understand why make your life harder by
using GPL (which may lead to having to hire a lawyer somewhere in future
to defend yourself)
You don't need to defend yourself. You only need a lawyer if your code
makes use (by linking or any other means that makes it a derived work)
of GPL'd code, or if someone is not following the terms of your license.
4. in the special cases of perl, python, ruby? stuff, distribute "under the same terms as XXX itself".
Which _may_ make it incompatible with GPL. For instance, if a hypotetical
PHP module (distributed under the PHP license which is incompatible with
GPL- thus it breaks the GPL terms) links against libreadline, then it
breaks the GPL. This is just insane.
I don't know about PHP, but the Perl licensing terms are "Artistic or
GPL", so compatible. in doubt, I will rephrase: "under the same terms as
XXX versionYYY itself" (so the terms cannot change). You can, still,
say, "under the same terms as XXX, any version beyond YYY, or the GPL,
in case those terms don't include it" or somesuch.
Does one have to obtain some kind of exemption from any of the "sides"?
sides?
Yes, the OpenSSL folks are one side and the FSF folks the other, for
instance. To use OpenSSL in a GPL-ed project (like Caudium, for
instance) I have to get an exemption from OpenSSL to use it with a GPL-ed project.
Yes. You have to get another license (one that is compatible with the
GPL). An exemption is just another different license. I don't know if
OpenSSL gives this type of exemption, let me see---
from http://www.openssl.org/support/faq.html#LEGAL2 ::
-- quote --
/2. Can I use OpenSSL with GPL software?/
On many systems including the major Linux and BSD distributions, yes
(the GPL does not place restrictions on using libraries that are part of
the normal operating system distribution).
On other systems, the situation is less clear. Some GPL software
copyright holders claim that you infringe on their rights if you use
OpenSSL with their software on operating systems that don't normally
include OpenSSL.
If you develop open source software that uses OpenSSL, you may find it
useful to choose an other license than the GPL, or state explicitly that
"This program is released under the GPL with the additional exemption
that compiling, linking, and/or using OpenSSL is allowed." If you are
using GPL software developed by others, you may want to ask the
copyright holder for permission to use their software with OpenSSL.
-- end quote --
not reeaaly simple, but that's it.
Mind you, the OpenSSL and SSLeay developers licensed OpenSSL saying: we
want you to advertise some things in the derived works. (clauses 3 and 4
/ SSLeay license, 3 / OpenSSL license). The GPL forbids that, hence the
incompatibity.
confused,
yes you are :-)
yes, because I'm starting to spend more time resolving legal issues which
don't interest me at all than developing code. This is just sick.
marek
You are 100% right. This is sick.
[]s, HTH, Massa
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