RE: how about mutual compatibility between Linux's GPLv2 and GPLv3?

["David Schwartz" <davids@webmaster.com>]

> Let's hope courts see it this way.

> But then, why is it that I can't use hardware to stop someone from
> copying or modifying the source code, but I can use hardware to stop
> someone from copying or modifying the binary?  Or is that not so?

You can use the hardware to stop someone from copying or modifying some
particular copy of the source code, so long as there is some copy of the
source code they can copy and modify. You are equivocating between a
particular copy and any copy at all.

The GPL requires the source code to be provided in a customary way and be
the preferred form for making modifications. It grants you the right to copy
and distrbute the source code. One accessible copy and no copyright
impediments should be all you need. The "further restriction" section solves
the issue of various workarounds to this.

Having access to the source code, being able to copy and modify it, being
able to incorporate bits of the source code in other GPL projects -- these
are all fundamental GPL rights. I do not see how anyone can get away with
encumbering these.

> Remember, section 2 talks about modifying *your* *copies* of the
> Program, without any reference whatsoever as to whether they're in
> source or object form.

I agree. You have the legal GPL right to modify any copy of a GPL'd work,
provided no technical or authorization obstacles stand in your way. If the
source code is on CDROM, you cannot modify that particular copy even though
you have the legal right to modify "the source code". You have the right to
copy it to someplace where no obstacles prevent you from modifying it.

The GPL grants you a right of access to the source code that is a genuine
guaranteed ability. The GPL also grants you the right to modify the source
code, but that is a legal right, not a guaranteed ability.

The GPL does sometimes use the word "may" where it's not clear whether it
means you have permission or you must be able to. The general rule of
construction is that "may" means permission, unless there's some clear
indication to the contrary. The "may"s in sections one and two are
permisssion against a claim of copyright enfrocement. The "further
restriction" clause is, at it states, only on the exercise of *rights*
(which I think means those rights licensed to you under copyright law,
namely the right of distribution and copying).

DS