[Asterisk-Dev] asterisk application license

[Peter Svensson]

On Fri, 1 Oct 2004, Kevin P. Fleming wrote:

> However, if you write code that is _distributed_ (in either source or 
> binary form), and that code is intended for, and would only work while, 
> being an Asterisk plug-in module, then you must license the source code 
> as GPL or LGPL. This is because any such code would be considered a 
> "derivative work" of Asterisk, and you obtained Asterisk under a GPL 
> license. If you distribute binaries of your code, you must make the 
> source available to users of your binaries, and they have the implicit 
> permission to redistribute that source as long as they acknowledge where 
> they obtained it.

The original question was in part regarding applications built on Asterisk
through the AGI and similar interfaces. My gut feeling is that those would
not be considered a derived work any more than a shell script is a derived
work of the shell.  Given the language if the GPL this seems to be the
expressed intent of the license.

The copyright law would seem to support the position that a program is not 
automatically a derived work of another program by simply using only 
using the defined normal interface of the second program. If the output 
contains copyrightable material things get dicy, but that is not the case 
with Asterisk.

The law is actually not crystal clear about what constitutes a derived
work in regard to program code and there have been rulings that seemingly
contradicts one another.

The safest thing to do would be to get in touch with Digium and other 
copyright holders or holders of sublicencing rights and ask them for a 
clarification on their intents.

Oh, and go see your lawyer in any case. 

Peter