Question for GNU-GPL experts

[Dirt]

The GNU C library is licensed under LGPL, not GPL.

--Jon

Those aren't the only libs around...

GPLed static libraries pretty clearly can't be used in programs that are distributed under a non-GPL license. The LGPL is used when this restriction is not desired.

[Dirt]

(it seems indeed to need a true lawyer for a safe answer ... )

Unless you have the will and the means to fight this out in court, the safe answer is to back down. If you are willing to go ahead it could make you famous, as it might set the precedent in this situation.

[F.Huber]

Thanks for your answer!

The GPL only applies when distribution occurs. You aren't distributing any GPL software (unless the engine.dll link you mention in 3) is distributed by you), so you aren't bound by the GPL in this case.

I don´t understand what you mean by "unless the engine.dll link you mention in 3) is distributed by you"!?
The engine.dll or the link to it?
Of course I didn´t distribute the engine.dll itself, in the included readme.txt I´ve only mentioned the URL of the website from where the complete package (containing this DLL with all its sources) can be downloaded.

GPL Wiki under "The GPL in court."

Wow, a very interesting link which is covering exactly my problem (i.e. dynamically linking to a GPL´ed program library).
But unfortunately from all those different opinions and court decisions there´s only one conclusion: not even the ´experts´ exactly know how to handle this case!

Well, in the meantime I´ve already removed my program again from my website - I´m absolutely not keen on having to fight on court for the right to publish it.

It´s really a strange world nowadays:
You´re writing a great program, want to make it free available to everyone, and instead of some praise or a simple "thanks" you only get massive complaints about a ´supposed´ copyright or license violation!

[jdart]

GPLed static libraries pretty clearly can't be used in programs that are distributed under a non-GPL license. The LGPL is used when this restriction is not desired.

Actually FSF would like to say there is no difference between the license implications of static and dynamic linking. Remember, RMS thinks proprietary, closed-source software should not even exist. He is not in the least interested in facilitating it.

As a practical matter, though, there are very few libraries in any Linux distribution that are under GPL and not LGPL or another permissive license. glibc is LGPL. So are X libraries. So is GNOME. OpenSSL is BSD-like. etc.

[Graham Banks]

It´s really a strange world nowadays:
You´re writing a great program, want to make it free available to everyone, and instead of some praise or a simple "thanks" you only get massive complaints about a ´supposed´ copyright or license violation!

Yep.

[bnemias]

I don´t understand what you mean by "unless the engine.dll link you mention in 3) is distributed by you"!?
The engine.dll or the link to it?
Of course I didn´t distribute the engine.dll itself, in the included readme.txt I´ve only mentioned the URL of the website from where the complete package (containing this DLL with all its sources) can be downloaded.

I meant the dll itself. I don't see how a link to some other site could constitute distribution. But I would be safe and omit the link too. Besides, if your program works only with engine.dll, then anyone seeking out your program probably already has engine.dll.

[Dirt]

Actually FSF would like to say there is no difference between the license implications of static and dynamic linking.

But is the FSF right? With a static library you are yourself distributing GPLed material, so I think that's clear. With a DLL it comes down to what is a derived work, and I'm not aware of this question being completely settled legally. The FSF might be right, but I wouldn't call it clear.

[jdart]

I think (personal opinion) it is correct to say it is not settled. But everyone is going to have judge for themselves what level of risk dynamic linking to GPL code would entail.

Note that GPL v. 3 has some more explict language about dynamic linking, vs. GPL v. 2.

--Jon

[bob]

GPLed static libraries pretty clearly can't be used in programs that are distributed under a non-GPL license. The LGPL is used when this restriction is not desired.

Actually FSF would like to say there is no difference between the license implications of static and dynamic linking. Remember, RMS thinks proprietary, closed-source software should not even exist. He is not in the least interested in facilitating it.

As a practical matter, though, there are very few libraries in any Linux distribution that are under GPL and not LGPL or another permissive license. glibc is LGPL. So are X libraries. So is GNOME. OpenSSL is BSD-like. etc.

I'm talking commercial products that run under linux, not linux distributions themselves...

[Aleks Peshkov]

It´s really a strange world nowadays:
You´re writing a great program, want to make it free available to everyone, and instead of some praise or a simple "thanks" you only get massive complaints about a ´supposed´ copyright or license violation!

A costless program is not equal to a free program from FSF point of view. You are free to not use Engine.dll, but you are not free to distribute a derived proprietary work from a free code.

I personally do not know any GPLed chess engine that exist in DLL form. I think it is safe and nice for all to change the source of DLL engine to make it UCI/Winboard compatible console program, so all programmers will benefit, not only your own GUI.