Subject: Re: Reverse Engineering and Derived Works in Open Source Licenses?
From: Rick Moen <>
Date: Fri, 7 Mar 2003 01:27:05 -0800

Quoting James Michael DuPont (

> Does anyone care to comment?

Matt Welsh's observation amounts to saying that the GPL (and, by
extension, other licences) place no impediment on writing an independent
implementation of the same idea.  That's true.  It's a clear consequence
of copyright law wither or without UCC 2B.  That's what makes copyrights
different from patents.

(I'm making no comment on licences that purport to forbid or restrict

> The GPL is based on the assumption that any derived work based on GPL'd
> software must make use of the source code, which is not necessarily
> true.

A work created by observing how the original functions, and then
independently writing code that performs the same function, is not a
"derivative work" in the sense defined in copyright law (and referred to
in the GPL text).

Cheers,      "Transported to a surreal landscape, a young girl kills the first
Rick Moen     woman she meets, and then teams up with three complete strangers       to kill again."  -- Rick Polito's That TV Guy column,
              describing the movie _The Wizard of Oz_
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