'GPL encumbrance problems' (jdow)

[John Summerfied]

Erwin Rol wrote:

> 
> The GPL kicks in if you distribute your product. If your program needs a
> GPL library the program is a derived work from that library and so if
> you distribute that program you have to distribute it in a GPL
> compatible way (for example by putting the program under the GPL).
> 
> If you have a LGPL library the use of that library is not seen as a
> derived work and hence you are free to choose the license for your
> program. 
> 
> 
>>What's good enough for the goose is good enough for the gander so the 
>>GPL zealots can't have it both ways.  Either implementing libraries that 
>>are compatible with existing Unix(tm) headers and interfaces violates 
>>someone's (say SCO's) copyrights or using GPLed headers and interfaces 

Whether it impinges on someone else's rights depends on the licence (say 
SCO) grant to those doing the (re)implementation and the rights (say 
SCO) actually have. Copyright and a licence to copy are not quite the same.

>>to GPLed libraries in proprietary code is legal.  That being said, the 
>>open source folks have a lot more to lose if headers and interfaces are 
>>suddenly found to be subject to copyright protection.
>>
> 
> 
> That headers aren't protected by copyright doesn't mean the

I don't believe that headers aren't protectable by copyright. However, 
if I provide you with some of my software, and I include headers 
(describing an interface to my software), then you are entitled to use 
those headers to write your software to interface to mine.

The terms under which you may _distribute_ your software is another 
matter altogether, and that matter is determined by the licence I grant you.

If I employ a BSD-style licence, then you can choose to use a similar 
licence yourself, to use a proprietary licence and to not provide your 
source, or even to distribute _your_ software, even as a derived work, 
under the terms of the GPL.

If, on another hand, I grant you use under the terms of the GPL, then 
you are still free to write your software, but if you link your program 
with mine (isn't that what the headers are for?), then any distribution 
you do must be under the terms of the GPL, and you must (if asked) 
produce the source on demand.



> implementation of the logic behind those headers isn't protected by
> copyright. If you have a GPL library, copyright doesn't prevent you from
> rewriting (from scratch) that library with compatible headers. Copyright
> does however prevents you from using that GPL library in a way that is
> not compatible with its license.  

I think you would need to be very careful with your compatible headers, 
especially if the headers you're cloning are entirely devoid of 
comments. But, IANAL.


On the whole, the GPL serves us well, but it's not for everyone or for 
everyprogram.

Some years ago, I wrote a program, and then made some changes, and could 
have sold licences to others (I checked with a lawyer on that one[1]). 
My marketplace was a subset of the users of Facom computers in Australia 
- they were not, AFAIK, sold in the USA or anywhere else except NZ (I 
think) and Japan (where language, culture and being unknown all counted 
against me). I reckon, at best, a dozen sales.

There'd be no money at all for me if I licenced it under the GPL or 
other freely-distributable licence (the GPL, I might add, didn't exist 
back then), because the likelihood of anyone wanting changes were fairly 
remote.

[1]Facom's lawyers had a different take, but we simply glared at each 
other, and Facom didn't actually take any action to get in my way.

Over the years I've come to the conclusion that my lawyer didn't really 
understand the situation.


-- 

Cheers
John

-- spambait
1aaaaaaa at computerdatasafe.com.au  Z1aaaaaaa at computerdatasafe.com.au
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