Subject: Re: Identifying my version of a GPL program
From: Richard Stallman <rms@gnu.org>
Date: Fri, 22 Dec 2000 22:09:08 -0700 (MST)

I think that a contract to provide support for, or work with, a
certain computer only so long as the software on it is not changed is
a reasonable thing to do in some cases, and it does not conflict with
the GPL.