Combining GPL and non-GPL code

[Chuck Swiger]

Hi, Andy & all--

On Aug 17, 2007, at 2:42 PM, Wilson, Andrew wrote:
> 2. John Cowan and I, along with several other contributors, walked  
> our way
>    through the question of which license applies to a program where  
> GPL and
>    BSD code have been intermingled at the source level within a module
>    (not at the multiple file or archive level).  After looking at  
> some length at
>    the issue from a variety of different points of view, I think it is
>    fair to say that John and I and the other contributors agreed
>    the answer is "GPL."

While I agree that we have discussed this topic before, I believe you  
might be oversimplifying the end consensus (to whatever extent this  
is ever reached :) just a bit.  My answer to the above would be "both  
BSDL and GPL".  Since all of the requirements from the BSD license  
are a subset of the requirements of the GPL, your answer is also right.

However, the portion of the code which started off as BSDL code  
remains available under the terms of that license alone, and any  
derived work which uses a significant portion of the BSDL code must  
retain the BSD license text, original copyright notices, the mention  
in the documentation or other materials if a binary form of  
redistribution occurs, etc.

> 3. The concept that the BSD copyright allows relicensing is one of the
> more difficult points of open source licensing to get one's mind  
> around.

The BSD license does not mention relicensing anywhere, only:  
"Redistribution and use in source and binary forms, with or without  
modification, are permitted provided...."

It is commonly understood that this permits people to modify BSD  
licensed code and place the resulting derivative work under the terms  
of another license so long as the other license preserves the  
original copyright notice and BSD license text.  I would term this  
"sublicensing".

-- 
-Chuck