[jdev] Jabberd 1.4.x license concerns/questions

[Tijl Houtbeckers]

On Sat, 02 Apr 2005 01:22:40 +0200, Ralph Giles <giles at xiph.org> wrote:

> On Sat, Apr 02, 2005 at 01:02:08AM +0200, Tijl Houtbeckers wrote:
>
>> They're clearly not talking about a copyright notice on top of a source
>> file here. If you mention it in an advertisement you have to credit  
>> them,
>> if you distribute a binary (in the case of GPL you are NOT required to
>> include the source) you must credit them. etc.
>
> But how is this different from the BSD clause:
>
> * Redistributions in binary form must reproduce the above copyright
>   notice, this list of conditions and the following disclaimer in the
>   documentation and/or other materials provided with the distribution.
>
> That was the substance of my question. Is this not a similar limitation
> on distribution imposed by the license? Why is this GPL-compatible, when
> the advertising clause is not?

The GPL also requires you to show the GPL license (with your binary too!).  
It does not prohibit you from requiring to showing additional licence  
terms as long as:

- the requirments are NOT for any GPL licened code. (and it's not, it's  
just for the orginal BSD licensed code, not for the changes made to it..  
you can distrubite those changes WITHOUT showing the BSD license)

- the requirments do not cause any incompatibilities with the GPL. In  
other words there are no requirments over the code that make it  
"unlinkable" for GPL code.

The thing you seem to have trouble with, is that your required to show the  
license for BSD code. Remember, this license is not shown for the parts of  
your code that are GPL, but only those that are BSD. The GPL only makes  
certain requirments (that there are no restrictions that are not allowed  
for GPLed code) of the code it is linked with, it doesn't mandate that  
GPLed code can only be linked with GPLed code. The fact that using BSD  
licensed code requires you to show the BSD license (only) for the parts of  
your code that were licensed under the BSD license (ok, my sincerly  
apologise for that sentence) is not simply not disallowed anywhere in the  
GPL license. It's just a license. That fact that the license requires  
"itself" doesn't mean there's anything you can't do with the source or the  
derived binary. You just need the license, to get a license after all :)

the OpenSSL license is clearly different, it tries to impose licensing  
terms on use of it's code, that are not allowed in the GPL. It sets terms  
not just for it's own code, but for other (in this case, GPL licensed)  
code that uses it. Which the GPL does not allow.