Re: Licensing question

Christoph Lampert wrote:
> Hi,
> 
>>On 3/9/06, Chris <[email protected]> wrote:

>>>
>>>according to the GPL if my app loads xvid or similar then it must be open
>>>source.
> 
> 
> No. GPL does not restrict the _usage_ of the codec in any kind. If a 
> user has XviD installed on his/her machine, your program is free to
> use it.

I agree with this.


> 
> What you are not allowed to do is _distribute_ XviD together with a
> proprietary software, i.e. make a bundle for download, 
> have your player's installer directly install XviD as well, 

No thats is quite incorrect.

You are referring to the mere aggregation of the work. That it is installed onto a machine by a 
common installer does not bring the works under the GPL.

from the gpl...

In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
..........



The gpl uses the words "based on" for a program to come under the gpl it must be derived from 
the gpl'd works.


from section 0 of the GPL....

The "Program", below, refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.  (Hereinafter, translation is included without limitation in
the term "modification".)  Each licensee is addressed as "you".
.............

Thus a work must be based upon at least in part the gpl'd software. Thus if your program "Makes 
use of" but is not derived from (think parent child relationship) then even static linking is an 
acceptable method of making use of the software without ever being derived from the gpl'd 
software. I searched for the phrase static or dynamic and neither are mentioned in the licence 
thus neither or included nor excluded from the licence.

Clearly making use of a codec does not fall into this category, even if they are distributed on 
the same medium.

Interestingly the video encoded using xvid MUST be gpl'd as it is clearly "based upon or derived 
from" the gpl'd software. so all videos encoded using xvid MUST carry the appropriate copyright 
and licence clearly displayed as is specified in the GPL.



My error was to read the FAQ it is in fact quite inaccurate in its portrayal of the licence. the 
FAQ even on the gnu.org site is also innacurate and represents at best an idealised view of the 
licence.

The licence is quite clearly in its design and intent meant to prevent the use or modification 
of the open source software with the purpose of then making it closed source. in other words one 
cannot take xvid make some minor changes call it chrisvid and publish it as their own work.

I am sorry for the bother I have caused. I should have read the licence itself rather than take 
the shortcut of relying on someones interpretation of the licence, ie The gnu GPL faq.

Chris