Adrian Bunk wrote on Mon, Sep 17, 2007 at 02:57:14PM +0200:
> But stating in your licence that noone has to give back but then

quoted text
> complaining to some people on ethical grounds that they should give

> back is simply dishonest.

>

> Is your intention to allow people to include your code into GPL'ed code

> and never give back, or is your intention that this shouldn't happen?

>

> And whatever your intention is should be stated in your licence.

As this is a recurring argument in the present discussion, let's

address it, even though it lies somewhat beside the main topic.

What i wish and what i try to enforce by legal contracts are two

completely different things.  In particular, it is _not_ a smart

idea to try to enforce all one's wishes by legal means.
For example, i wish that as much as possible of the code i write be

freely available such that others can use it, too, and i wish that

others write useful code and make it free such that i can use it.

When i publish code, i wish bugfixes to be fed back to me, and i

hope that others might free their derivative works, too.  Besides,

i might hope that people at large behave in human and rational ways

and refrain from doing harm to others.  In particular i might wish

the fruits of my work not to be abused to harm or oppress people.

Quite probably, lots of software developers share similar wishes,

whatever licenses they happen to be employing.
But this doesn't imply i should be putting any of the above into

the license for my code.  Once people attach additional conditions

to their licences, sooner or later i get stuck when trying to

combine different code covered by different licences.  However well

intentioned, in practice, those additional conditions habitually

turn out to be incompatible - even when, regarded seperately, all

of them might appear to make some sense.
Now doubtless, the two main additional conditions imposed by the GPL -

derivative works may only be distributed if they are made as open and

as free as the original - are among those making the most sense of all

the additional conditions you might imagine, in the sense that nearly

any developer of free software will wish that anybody holding the

copyright on a derivative work would make that free.  Still, when

trying to combine code with different licences, even the GPL at times

turns out to be a bother.  This does not only apply to the case of

non-free closed-source commercial code, but also to cases where

authors intended to make their code free, but, be it by inexperience

or because they failed to restrain themselves, unfortunately added

some uncommon condition to the license.  Combining such code with ISC

or BSD code is hardly ever problem, combining such code with GPL code

may well be.
Thus, even when wishing derivative works to be free in their turn,

i still see a strong theoretical and a strong practical argument to

choose the ISC license over the GPL: Theoretically, it's just the

categorical imperative: If everybody would be adding her or his

favorite condition to her or his license, we would not end up in

free software, but in chaos.  Practically, i'm quite fed up with

GPL license incompatibility issues always popping up at the most

inconvenient places, and still more, with all those license

compatibility discussions.  With the ISC license, there are no

incompatibility issues and no incompatibility discussions, it just

works.  Of course, i lose the option to sue people to open up

derivative works, but i keep the hope that some people (especially

those engaged in free software themselves) understand and keep up

the spirit, and above all, i avoid lots of legalese worries.

Ultimately, it's kind of a trade-off.
To summarize, there are valid reasons to wish that people would make

derivative works free, but to not require it in the license.  Just

like there are valid reasons to wish that people should not use the

code for waging war, but to not require that in the license.