[Asterisk-Dev] GPL Licensing Question

[Steven Critchfield]

First, learn about non HTML mail. Turn on line wraps.

On Fri, 2004-10-15 at 15:28 -0600, Michael Giagnocavo wrote:
> I understand that Asterisk is GPL’d, but Digium retains copyright, and
> thus can grant exceptions. So a company would need this if they
> modified the Asterisk code and wanted to sell it as a proprietary,
> closed-source solution. On the other end, anything just using Asterisk
> formats or protocols (say IAX, dropping a .call file in the outgoing
> spool, or editing .conf) wouldn’t need any licensing.

All code in the official Digium released asterisk tree is either
copyright Digium and employees, licensed to Digium in a way where Digium
can use it royalty free, or is BSD or similarly licensed. This allows
Digium the ability to sell licenses that are free of GPL restrictions.

> How exactly does this work in regards to modules? As I understand,
> code that links to GPL code needs to be GPL also. Does this mean I
> can’t write a module that links to Mono (which is LGPL and MIT X11
> licensed) even if my module code is GPL? 

LGPL and GPL are compatible, MIT and BSD are GPL compatible although the
resulting code must be GPLed. Not familiar with the X11 license other
than a little about the new flap that created X.org out of XFree.

If you wish to make a module that links with asterisk and wish to
distribute it, you either must pay Digium for that right or you must
make the code GPL. 

This all has been covered before and is easily accessable in the archive
with the help of google. It is also important if you had to ask these
questions and wish to sell a product to go consult a lawyer as to your
rights under the various software licenses. Anything less is
irresponsible as a business. 

-- 
Steven Critchfield <critch at basesys.com>