From:	Allison Randal	Date:	Fri Apr 28 09:18:34 2006
Subject:	upstream license compatibility (was Re: compilation copyright)

On Apr 26, 2006, at 18:40, C. Garrett Goebel wrote:

> Audrey Tang's recent blog entry mentions her decision to move Pugs  
> away
> from Artistic 2 licensing because of Artistic 2 compilation copyright
> licensing conflicts between inclusion of Pugs source into Perl6/ 
> Artistic2
> and Pugs's inclusion of LGPL code in its source tree.

Clarification: Pugs isn't moving away from Artistic 2 licensing and  
compilation copyright has nothing to do with licensing compatibility.  
There was a good bit of confusion there for a few days, but we sorted  
it out.

> Q1: Could you explain why the inclusion of LGPL code into an otherwise
> Artistic2 source tree is legally dangerous?

This isn't specific to the Artistic License (in any version), it's a  
general legal principle. You can't give away rights you don't have. So:

1) You can include a free software package in another free software  
package with the same license.

2) You can include a free software package in another free software  
package with a more restrictive license (because you're giving away  
fewer rights than they gave you).

3) You can't include a free software package in another free software  
package with a less restrictive license (because you would be giving  
away rights that they never gave you).


Artistic 2 is less restrictive than LGPL, so that particular  
combination falls under 3. But, Artistic 2 code can link to LGPL  
code, which is all you need in most cases.

Allison