I'm one of the AROS (http://aros.sf.net/) developers, and I'm here to ask something about the AROS Public License (APL) and indirectly about the MPL, which the APL derives from (basically, everything is kept intact, apart from the Mozilla refereces changed into AROS references).
From my understanding of the license, people are allowed to modify the source code as long as they provide the sources of their modifications, where "modifications" means:
"any addition to or deletion from the substance or structure of
either the Original Code or any previous Modifications. When
Covered Code is released as a series of files, a Modification is: A. Any addition to or deletion from the contents of a file
containing Original Code or previous Modifications. B. Any new file that contains any part of the Original Code or
previous Modifications."Now, look at this situation.
Say I have a set of files, named A. Now, Mr. Brown takes these files, modifies them, and produces a new set of files which is the union of A' and B, where A' is the set of files which are the modifications of the files in the set A, and B is a set of new files.
As I understand it, Mr. Brown only has to release the sources of A', right? If I'm right, please follow me: what happens if A' _doesn't_ work without B? In other words, if Mr. Brown modified A in such a way that now A' depends on B and B depends on A'? Is Mr. Brown still required to only open the sources of A'? If yes, isn't this a big hole in the license? If not, in which way exactly the license would require Mr. Brown to also opensource B?
In yet other words, do the modified sources need to be completely functional, or can they also not work at all without the "proprietary" part?
I say it would be a hole because, at all effects, you can't make use of the changes, hence they are worthless. At this point, why not just use BSD?
Regards, Fabio Alemagna
--
"Everything is vague to a degree you do not realize till you have tried
to make it precise"
Bertrand Russell
The Philosophy of Logical Atomism