Subject: Servers running modified versions of free programs
From: Richard Stallman <>
Date: Fri, 2 Jul 1999 21:09:35 -0400

I was forwarded a message from the list, which said this:

    > What I am trying to get at is a set of restrictions on how certain
    > software could be used or modified.  For example, let's take mapping
    > software, since Tim O'Reilly mentioned it in his original post.  I
    > write some new cool mapping software and put it under the GPL.  Yahoo
    > snaps it up and puts it on their site.  In fact, they enhance it.
    > They permit users to connect to it on their site, but they don't
    > distribute their changes.  Yahoo has now in some odd but meaningful
    > sense made a proprietary fork of my code, the very thing the GPL was
    > supposed to prevent.

I see this as somewhat of a problem too.  So perhaps the GPL should
have a requirement for release of the modified source code in such
cases--but I am not sure of that.  I see arguments for both sides.

Privacy is an important right.  People and organizations should
certainly have the right to make their own changes, and use them
privately without publishing them in any way.

Offering a service to the public is not private use, though.  It takes
the case out of the domain where the principal of privacy gives
legitimacy.  So I don't think privacy is a valid argument against
such a requirement, for services offered to the public.

However, it might still be that a requirement like this is too
meddlesome and not necessary.  I am not sure.

The other question, of course, is whether it is legally possible to
make this requirement based on copyright.  It may be possible because
copyright covers public display.  Using a program to offer a service
to the public could perhaps count as public display of the program.
I have not yet asked lawyers about this, though.