Re: License compatibility (was Re: [Pearpc-devel] Sebastian? Daniel?)

[Brian O. <bri...@te...>]

Here's some more interesting information from the GPL faq:

---
Q. What does it mean to say that two licenses are "compatible"?

A. In order to combine two programs (or substantial parts of them) into a  
larger work, you need to have permission to use both programs in this way.  
If the two programs' licenses permit this, they are compatible. If there  
is no way to satisfy both licenses at once, they are incompatible.

For some licenses, the way in which the combination is made may affect  
whether they are compatible--for instance, they may allow linking two  
modules together, but not allow merging their code into one module.


Q. What does it mean to say a license is "compatible with the GPL".

A. It means that the other license and the GNU GPL are compatible; you can  
combine code released under the other license with code released under the  
GNU GPL in one larger program.

The GPL permits such a combination provided it is released under the GNU  
GPL. The other license is compatible with the GPL if it permits this too.
---

So, the new, modified BSD license now permits inclusion of BSD licensed  
code into GPL licensed code (where before it did not permit this), and  
thus according to the GPL faq the BSD license is now "compatible" with the  
GPL license.

However, the problem, in my view, lies with the conditions of the BSD  
license still. My view is that these BSD conditions cannot be satisifed  
when linked into GPL code and released under GPL license.  So while the  
GPL license can be satisfied now, the BSD license cannot.  Here's why:

The BSD license has only 3 major sections: (1) a copyright, (2) a list of  
conditions, and (3) a disclaimer.  Part (2), the list of conditions,  
requires you to include the BSD license and it's conditions into the  
redistributed work.  So, you would have a license in your work that  
included the GPL *and* the BSD conditions.  Under contract law, you've  
thus *MODIFIED* the GPL license by act of inclusion, and now your GPL  
license has the BSD conditions attached to it.  However GPL section 2(b)  
states, in summary, that the Program must be released under the GPL  
license, only.  This is an exclusive license, and is not modifiable.  So  
you can't, in practice, satisfy *both* the GPL and the BSD license terms  
in a work that is linked into one executable.

-- Brian