Subject: Re: Assistance/advice in choosing a license for POV-Ray 4.0
From: "Rod Dixon, J.D., LL.M." <>
Date: Mon, 14 Nov 2005 10:33 -0500

I may be missing something in the issue you are raising.  Once the library 
finds its way onto an end-user's system (regardless of method of 
distribution or install), why does it matter to you that a commercial 
developer's software may call the dll? I am assuming that the license for 
the library would permit the end-user to "use" the library so there should 
be no end-user issue. As for the commercial developer, if you want to force 
the developer to disclose to the end-user that the dll is being used by the 
developer's program, you should solve this by coding the library to display 
a notice - - of course, this seems like an odd thing to do, but it's your 
library.  On  the other hand, if your concern - -  as the copyright holder 
- - is whether the commercial developer may infringe the copyright in the 
dll, we are back to a question that is fact-intensive and not well-settled.

- Rod
Rod Dixon

...... Original Message .......
On Mon, 14 Nov 2005 16:16:02 +1100 Chris Cason <> wrote:
>Rod Dixon, J.D., LL.M. wrote:
>> "Must be no..." does not quite acknowledge that the answer is not 
>> well-settled (at least in the United States).   
>I was worried someone might say that :-(
>Frankly, despite the fact that it technically would suit our project from
>a license point of view if it were, I really would not like to see this
>become case law, mainly because of the can of worms it would potentially
>> We should be careful to acknowledge that your question potentially 
>> two distinct works: the modification and the program generated by 
>> Regarding the former, attention to the linking issue is an unnecessary 
>> distraction.  
>> If a contributer creates an original work on the basis of rather trivial 
>> use of the covered open source program, it probably will be irrelevant 
>> this is done (that is, whether by static or dynamic linking) as far as 
>> open source licensor's copyright interests are concerned. 
>>  Regarding the latter - - the program generated by dynamic  linking - - 
>> agree that it is unlikely that the result will be a derivative work, but 
>> the answer depends upon a fact-intensive analysis of what is created by 
>> linking.
>One circumstance we need to look at is the case where there is no
>modification. Suppose in the future there is a standard which
>is either present by default on a wide range of *nix-like systems (which,
>BTW, is something I would like to see happen), or can be trivially
>installed (e.g. under FreeBSD potentially I could just type 'pkg_add -r
>libpov', or something similar). Let's also say for the sake of example
>this library is LGPL'd.
>Suppose someone releases a commercial CAD program that depends on this.
>There is no need to ship libpov with the app since if it's not there, the
>end user either installs it themselves, or a sufficiently smart installer
>could auto-fetch the dependency and install it (in fact the FreeBSD ports
>system can do exactly this).
>In the above case it appears to me there is no requirement on the vendor
>to acknowledge in any way whatsoever the use of libpov*. On the windows
>platform the same could apply; the installer could just download an
>official binary from e.g. our site and off they go.
>I note of course that this is already physically possible, in that it's
>feasible for an installer to download the Windows version of POV-Ray, and
>once installed, for an application to generate renders via command-line
>parameters or sending windows messages. Provided the POV installer is not
>bypassed, the user has to accept our license, which makes them aware they
>are getting a free app, which is good.
>However if the vendor's installer bypasses our installer (e.g. by
>directly extracting the files, or just hitting 'ok' automatically in each
>dialog), it is unclear to me who is responsible. The user has some IP
>on their system for which they have not been granted a license and for
>which they have not paid (meaning that in most places, they have no
>common-law rights to use it, though IANAL so take that with a grain of 
>If they fire up their CAD program, and the CAD program unbeknownst to
>them fires up POV to do renders, who is actually responsible for
>'running' the unlicensed software ??? Who is responsible for installing
>it in the first place ? It seems to me that legally it may be the end-
>user who did the CAD app install, which is probably not the most
>desirable outcome from my point of view (though if that is the case, then
>at the very least there is an argument that the vendor may have induced
>any violation for which the end-user is held responsible, which isn't
>likely to make them very popular with their customers).
>While the above may seem hypothetical, I can say we have recently been
>faced with this exact situation. And it could easily be applied to just
>about any other software that has an API that can be accessed without
>static linking - from a shared library with a formal exported API to an
>executable that takes command-line parameters.
>(To make things even more convoluted, under Windows, at least, there is
>no practical difference between a DLL and an EXE. Both use an identical
>file format and it is entirely possible to load and manipulate an EXE as
>if it were a DLL).
>I've put a fair bit of thought into the issue of third-party execution of
>a POV binary (be it EXE or DLL) over the years and frankly I have yet to
>come up with a clean way of solving the generic problem that this poses
>with respect to intellectual property ... if there is a legal way for the
>code to end up on the target system it appears all bets are off from that
>point (I really hope someone will pop up and show me I'm wrong here ...)
>> For reference: take a look at a couple of cases like  Lewis Galoob Toys 
>> Nintendo and/or Microstar v. Formgen. 
>I will look these up.
>-- Chris
>* from a purely personal point of view, if libpov were a fairly standard
>  library, lack of acknowledgement on the part of apps using it on
>  FOSS platforms would not bother me nearly as much as if it happened
>  on windows ... I guess this is mainly due to the fact that for example
>  GNU/Linux is built on so much free software, that it's almost a given
>  that any app running on the OS is going to depend on a whole bunch
>  of work by folks who get little or no credit, if for no other reason
>  than it's not practical to specifically credit them all in an about box
>  or copyright notice.