Is inherited class a derivative work?

Angelo Schneider angelo.schneider at
Thu Oct 18 09:32:59 UTC 2001

Hi all!

"Forrest J. Cavalier III" wrote:
> >
> > The discussion on this topic has been very interesting. I am unsure who posted
> > the comment about the lawyers at FSF, but if that person could obtain clearance
> > to post the complete explanation on why FSF has taken the position that the use
> > of inheritance constitutes the creation of a derivative work, this might be
> > extremely helpful for our discussion.  If this is a reliable legal position, it
> > might discourage use of the GNU GPL. Hence, this is a rather important matter.
> >

Indeed that is interestng! Especialy if there are court rulings!

> I think this fits with RMS and FSF previously published
> ideas (which were not from lawyers.)
> For years RMS and the FSF have the stance that if there is only one
> implementation of a library/API, and you write something which
> links to it, your work is a derivative work of that library.
> I expect the RMS/FSF reasoning is consistent in the case of
> inherited class.

As I pointed out allready: linking to an API is not, I repeat: not a
derived work.
"derived work" is a legal term. You can not redefine it in your license.

If you like to say: in the sence of our lisence your work is "based on"
our work if you link to it ....
That you can do, of course. But: legal terms are hard to be redefined
without shooting your self into your knee.

I include a quote from a prvious message: 
by Lawrence E. Rosen[SMTP:LROSEN at ROSENLAW.COM]

  A "derivative work" is a work based upon one or more preexisting
   such as a translation, musical arrangment, dramatization,
   motion picture version, sound recording, art reproduction,
   condensation, or any other form in which a work may be recast,
   transformed, or adapted.  A work consisting of editorial revisions,
   annotations, elaborations, or other modifications which, as a whole,
   represent an original work of authorship, is a "derivative work."
   17 USC § 101.  

Probably you see that "the character of the original work" still is
easyly recognizeable in ane form of derived work.
You can say the essence of the original work shines through the
reworking (reworking creates a derived work).

How do you like to construct a case of derived work by calling an API?
Is that a "transaltion" of the library?
Is that a new [deleted musical] "arangement" of that library (source
Is that a "dramatization" of that librarty if you write code calling it?
Is it a fictionalization?

Look at the end of the legal paragraph, here in is the key: 
Derived work is "any [other] form in which a work may be recast,
transformed, or adapted".
Derived work is: "editorial revisions, annotations, elaborations, or
other modifications" even if they represent a own work.

So: how may a call to an API, which surely may be a heavy use, the whole
work may be unthinkable without that API, but how may this be a "derived
work"? No modifications, adaptions, elaboratons. annotations, recasting,
transforming of the original work!

Even more: how may using inheritance be a derived work? (If we leave out
that in the end you link the library or your derived class wont work).

In most programming languages you only use *one* keyword plus the name
of the base class to derive a class from: that would just be a citation
of the class name.
Citation is fair use, and a one word citation is (legaly) not even
considered to be a citation.

Finaly, (I said this at least 4 times on the list during the alst days)
as long as you do not take one original source file from said library
and modify THAT file, you make no derived work. NO, this is not my
opinion, that is legal fact.


P.S. how to change my mail adress on the list?
I'm there as angelo.schneider at and ywould like to be there as
angelo.schneider at

Angelo Schneider         OOAD/UML         Angelo.Schneider at
Putlitzstr. 24       Patterns/FrameWorks          Fon: +49 721 9812465
76137 Karlsruhe           C++/JAVA                Fax: +49 721 9812467
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