[jdev] Jabberd 1.4.x license concerns/questions

[Tijl Houtbeckers]

On Fri, 01 Apr 2005 20:39:49 +0200, Ralph Giles <giles at xiph.org> wrote:

> On Fri, Apr 01, 2005 at 08:35:15PM +0200, Tijl Houtbeckers wrote:
>
>> The GPL license prohibits any restrictions other than those of the GPL
>> license itself.
>
> Off topic, but I've always been confused why the advertising clause was
> considered an unacceptable restriction, while the MIT/BSD requirement to
> reproduce the license itself was not. Can someone clarify the
> distinction?

The MIT and "new" BSD license have terms and conditions that are  
compatible with the GPL. You are allowed to do the same things with the  
code as with the GPL (the GPL is just MORE restrictive about it).  
Something written under the "new" BSD or MIT license will never become GPL  
code (unless the copyright holder agrees to that). However, they allow any  
modifications to the source to be under a different license.

The fact that MIT and BSD require the inclusion of their license for  
*their part* of the source (not of modifications to it!) is not  
disallowed, because none of those restrictions go against the GPL  
restrictions. The ONLY restrictions in the MIT and BSD license are the  
copyright notice, the no warranty disclaimer, both which the GPL license  
encourages you or even requires you to include. Except the final  
restriction is that you should reproduce these restrictions, but since all  
of those restrictions are GPL compatible.. you're allowed to include them.

The "old" BSD license, and the OpenSSL make conditions on what you can do  
with the source, including changes, deratives, etc. of it. (you have to  
mention it when advertising (distribtion), you have to put some stuff  
somewhere in your source that displays you use their work). These  
restriction are not compatible with the GPL since the GPL requires you may  
not put any restrictions on GPLed code other than those in the GPL itself,  
or that you even link with code which is places restrictions on code that  
are not compatible with GPL restrictions.

in response to Jonathan, this is one of the reasons there is a "new" BSD  
license. The old one was not compatible with the GPL. The GPL *IS* written  
to deny people credit for their work. By that I mean, it is written  
specially so that I can take your GPL work, and use it, without ever  
having to credit you. Of course I'm allowed to credit you if I want, but  
the "freedom" concept behind the GPL is that the code is not "free" (and  
thus not GPL compatible) if you can REQUIRE that I must credit you. Which  
is exactly what the OpenSLL and "old" BSD license does. (Note that if I  
distribute  GPL derived software I must also make the source available,  
which MUST include your copyright notice, and I MUST document the changes  
I made; in other words, what's yours and what's mine).

To summerize, if you want your code to be useable with GPL code, you can  
put any type of restrictions on your code, including that they should be  
reproduced as long as:
- These restrictions only apply to the orignal source, not any changed  
made to it.
- These restrictions do not go against the requirments of licensing and  
distrubtion in the GPL. (the GPL can be stricter than your requirments,  
but you can not be stricter than the GPL requirments)

As a final note: the "new" BSD license sometimes places 1 additional  
requirment on the use of the source, relating to the naming of the  
software and use of the authors name. This is a grey area to me. I suspect  
this is not a problem because the fact that the GPL could never require  
you to license a trademark or your own name along with your software, nor  
does it explictly try to. For example, look at the Jabber trademark..

As some as you might have guessed already, IANAL...