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On “Free Hardware”

By Richard Stallman

A number of people have asked the GNU Project if we would like
to branch out from free software into free hardware designs, and
expressed their interest in working on them. Some people have even
suggested a project to make free chip designs.

To understand this issue clearly, recall that “free software” is
a matter of freedom, not price; broadly speaking, it means that
users are free to copy and modify the software. So if we try to
apply the same concept to hardware, “free hardware” means
hardware that users are free to copy and modify; a “free hardware
design” means a design that users are free to copy, modify, and
convert into hardware.

Free software is often available for zero price, since it often
costs you nothing to make your own copy. Thus the tendency to
confuse “free” with “gratis”. For hardware, the difference
between “free” and “gratis” is more clear-cut; you can’t
download hardware through the net, and we don’t have automatic
copiers for hardware. (Maybe nanotechnology will provide that
capability.) So you must expect that making fresh a copy of some
hardware will cost you, even if the hardware or design is free. The
parts will cost money, and only a very good friend is likely to
make circuit boards or solder wires and chips for you as a

Because copying hardware is so hard, the question of whether
we’re allowed to do it is not vitally important. I see no social
imperative for free hardware designs like the imperative for free
software. Freedom to copy software is an important right because it
is easy now–any computer user can do it. Freedom to copy hardware
is not as important, because copying hardware is hard to do.
Present-day chip and board fabrication technology resembles the
printing press. Copying hardware is as difficult as copying books
was in the age of the printing press, or more so. So the ethical
issue of copying hardware is more like the ethical issue of copying
books 50 years ago, than like the issue of copying software

However, a number of hardware ethusiasts are interested in
developing free hardware designs, either because they have fun
designing hardware, or because they want to customize. If you want
to work on this, it is a fine thing to do. The GNU volunteer
coordinators ( can put you in touch with other people
who share this interest. If organizations are formed for this
purpose, the GNU Project will refer interested people to them.

People often ask about the possibility of using the GNU GPL or
some other kind of copyleft for hardware designs.

Firmware such as programs for programmable logic devices or
microcoded machines are software, and can be copylefted like any
other software. For actual circuits, though, the matter is more

Circuits cannot be copylefted because they cannot be
copyrighted. Definitions of circuits written in HDL (hardware
definition languages) can be copylefted, but the copyleft covers
only the expression of the definition, not the circuit itself.
Likewise, a drawing or layout of a circuit can be copylefted, but
this only covers the drawing or layout, not the circuit itself.
What this means is that anyone can legally draw the same circuit
topology in a different-looking way, or write a different HDL
definition which produces the same circuit. Thus, the strength of
copyleft when applied to circuits is limited. However, copylefting
HDL definitions and printed circuit layouts may do some good

It is probably not possible to use patents for this purpose
either. Patents do not work like copyrights, and they are very
expensive to obtain.

Whether or not a hardware device’s internal design is free, it
is absolutely vital for its interface specifications to be free. We
can’t write free software to run the hardware without knowing how
to operate it. (Selling a piece of hardware, and refusing to tell
the customer how to use it, strikes me as unconscionable.) But that
is another issue.

Copyright 1999 Richard Stallman
Verbatim copying and redistribution of this entire article is
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