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Re: GPL and command-line libraries

On Sat, Nov 27, 2004 at 05:20:46PM +0100, Wesley W. Terpstra wrote:
> What is a binary image? I think it makes most sense that it includes the
> entire shipped product---both my executable and it's dependent: his.
> Whether the library and binary form a single file seems irrelevant.
> Otherwise, .dll's or .so's would also avoid this 'binary image' issue.
> What is the difference between 'dlopen' and 'system'?

You're almost right. The technical method by which derivation or
aggregation is accomplished is irrelevant. Varying the method will not
change the state from derivation to aggregation, or vice versa: ld is
not automatically derivation, nor is tar automatically aggregation.

The state of a work being derived is intrinsic to the work itself. It
doesn't become derived because you add a useless unnecessary -l
argument to the compiler, and it doesn't stop being derived because
you have a trained monkey copying the data around by hand between

When we talk about 'linking', we're really referencing the fact that
it's normally used in a certain way. It's not magic, it just happens
that linking to a library will normally occur in the cases where
you've got a derived work, because anything else is insane from a
technical perspective. Getting overly attached to the notion of
'linking' leads to navel-gazing exercises and not much else.

The exact determination of what is and is not derived is notoriously
fuzzy and ultimately a matter for the courts (yeah, copyright
sucks). I find a good rule of thumb to be: "If your application will
only work in the presence of some specific other code, it's a derived
work, otherwise it's not", which leads neatly to the library API

In essence: playing games at the interface boundary cannot exempt you
from license requirements. Only a sufficiently expensive lawyer can do

  .''`.  ** Debian GNU/Linux ** | Andrew Suffield
 : :' :  http://www.debian.org/ |
 `. `'                          |
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