The Open Source Definition: 3. Derived Works

[Forrest J Cavalier III]

Christoph Steinbeck <steinbeck at ice.mpg.de> wrote (in part)

> What is the point of letting them change the code and change the license
> to whatever they like (proprietory, e.g.).
> 

The other replies explained why the wording is "allow" instead
of "require" in OSD point #3.  They were accurate.

I think you asked a deeper question.  And a lot has been written
on the subject if you dig around.  (Lots of flame wars too, and
I don't want to start one here.)

In the big picture, 
  - existing copyright law creates very broad restrictions.  

  - A software license is permission to do something
    not already permitted by copyright law.  (Some licenses are
    written as contracts, which would mean that copyright law
    isn't the starting place.  The contract has all terms and
    conditions, and may even restrict something that was
    allowed under copyright laws.  )

  - Every license meeting the OSD must provide certain permissions.

  - The OSD allows other restrictions and permissions to be part
    of the license.  (This is where the GPL and BSD-style licenses
    differ.)

The way you phrased your question, it seems you already understand the
freedom-ensuring benefits of the GPL.

The BSD or MIT-style license provides the benefit of being able
to re-use software in proprietary works as well as open source
works.  Some authors find that benefit more compelling than
the benefits of the GPL.  

(If I say anything more, I'll be taken as a troll, I fear.  Trust
me, there has been a lot of discussion.  Should be easy to find.)

Forrest J. Cavalier III, Mib Software  Voice 570-992-8824 
http://www.rocketaware.com/ has over 30,000 links to  
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