How To Break The GPL

John Cowan jcowan at
Fri Mar 3 15:45:47 UTC 2000

This is offered in the spirit of "How To Make Atomic Bombs", and does
*not* mean that the author approves of the conduct described herein.

A close reading of the GPL suggests the following way to distribute
unfree software that contains GPL-specific components.

1.  Alice designs, debugs, and tests (but does not distribute)
    commercial software that uses a GPLed library that is copyrighted
    by Trent and publicly available from Trent's homepage.

2.  Alice distributes a compiled version of her code *only* to her
    paying customer, Bob, under a restrictive end-user license agreement.
    Trent's library is not included.

3.  Alice sends instructions (in English, sh, or make) that cause Bob's
    system to download Trent's library from its homepage and link it with
    Alice's modules.

Now who has violated Trent's copyright?  Not Alice: she did not modify or
distribute Trent's work.  Not Bob: he cannot distribute the executable
version because of Alice's license.  Bob might be said to have made a derivative
work, but only in the sense that Bob would make a derivative of a book by
Trent by writing marginal notes in a copy that he owns, a perfectly legitimate
behavior.  Nor would it matter if Bob marked up the book in accordance
with instructions sent him by Alice.  (If Bob tried to duplicate and sell the
marked-up book, Trent's copyright *would* be violated, but he doesn't.)

I would very much like to hear that there is a flaw in this logic.  If so,
where is it?


Schlingt dreifach einen Kreis vom dies! || John Cowan <jcowan at>
Schliesst euer Aug vor heiliger Schau,  ||
Denn er genoss vom Honig-Tau,           ||
Und trank die Milch vom Paradies.            -- Coleridge (tr. Politzer)

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