Subject: Re: Assistance/advice in choosing a license for POV-Ray 4.0
From: Chris Cason <>
Date: Thu, 24 Nov 2005 14:09:20 +1100

Ben Tilly wrote:
> There are purposes which you cannot distribute your software for.
> This is a problem who want to create a project which they want other
> people to build on and redistribute.

Can you give an example ? I think our terms as shown below are fairly
liberal. We allow derivatives as long as they are not complete 'rip it
apart and make something unrecognizable of the original distribution'.
(And if someone is going to do such a major job, that then it's no great
drama for them to remove POV or ask to be included in the definition).

> I read it.  IANAL, but I think that his complaint has merit.

> Sure, it is fine for Knoppix to create a CD with povray on it and
> distribute it.  But what if a magazine wanted to create a special
> version of Knoppix and redistribute that with their magazine?  One
> that includes Knoppix and some third party software on it?  Knoppix is

This is clearly allowed.

> for that purpose.  Including povray gets in the way of that goal.

With all due respect, I disagree. We put a lot of thought into our 3.6
license and I believe we succeeded in allowing the sort of things we
are discussing in this here.

> So you've given permission for povray to be included in knoppix.  But

*And* in other FOSS-based distros, including derivatives of knoppix.

> you *haven't* given permission for povray in knoppix to be used in the
> way that the knoppix folks want to see knoppix used.

Having read the license as you state, you would no doubt be aware of the
fact that the named distros (e.g. knoppix) are qualified with the phrase

  'without limiting the generality of the term, each of the
   following is a "generally recognized Distribution"'

Clearly this means that we're not just permitting those distros, but any
one that qualifies as per section 2 (see partial excerpt below).


     In return for the Distributor agreeing to be bound by the terms of
     this agreement, POV grants the Distributor permission to make a
     copy of the Software by including the Software in a generally
     recognized Distribution of a recognized operating system where the
     kernel of that operating system is made available under licensing

      (a) which are approved by the Open Source Initiative
          ( as complying with the "Open Source
          Definition" put forward by the Open Source Initiative; or

      (b) which comply with the "free software definition" of the Free
          Software Foundation (


Clearly, a derivative of Knoppix still complies with the above definition
(unless, it could be argued, it is so hacked that it no longer resembles
Knoppix, or alternatively that the kernel is no longer FOSS-based).

Note that we also say, in respect of magazine etc. distribution:

  [snip bit prohibiting magazine distribution]
  This clause 4.1(c) does not apply to Distributions permitted
  under clause 2;

meaning that magazines *can* distribute anything that qualifies under
clause 2, even if it's a 'special version with some third-party software
on it', as you put it.

I'm no lawyer either, but to me the specified parts of the license are
clearly readable and understandable, and I'm still not sure how folks
(even it seems yourself) come to the conclusion that we just permit the
named distributions in their trigonal form with no changes. This simply
is not the case.

In any case, Klaus's comments did not raise this issue, and if he had
done so I would have been happy to address it as best I could. Frankly
his wording seems fairly clear to me in that he appears to be under the
impression that distribution was impossible. Saying

  "The license is incompatible with a free distribution
   for any purpose, including commercial ones"

is pretty telling - the "for ANY purpose" kinda makes it clear the issue
isn't "I'm worried that some types of derivations of knoppix might fall
foul of the POV license but I understand that most uses are OK".

That said, what he does or doesn't believe isn't really an issue in the
context of this conversation; I merely made the point that rightly or
wrongly people are excluding POV-Ray from some places that it could be,
and we want to fix that by getting a new license. As Klaus pointed out in
that very same page, if we had an OSI-approved license he'd be a lot
happier, and this is exactly what we are trying to do; I'd rather not
veer off into a long discussion of what our current license does or
doesn't do except where it's directly relevent to the new license.

-- Chris