Re: Ocaml status?

[Henning Makholm <henning@makholm.net>]

Scripsit Lynn Winebarger <owinebar@free-expression.org>

> What's the status of Ocaml?

Somewhat unclear.

> I noticed parts of it were under GPL and other parts not.

Executive summary for debian-legal:

The ocaml compiler is written in its own language. It compiles
ocaml to bytecode, which is then executed by a bytecode interpreter
written in C.

The bytecode interpreter and the run-time libraries needed to
be linked with it are all GPL.

The ocaml source for the compiler itself is QPL.


Now, the QPL and the GPL are both DFSG-free licences, but they
are not compatible. That means that a *single* work cannot include
code which is GPL as well as QPL. Thus, the question is whether
the compiler *itself* is impossible to distribute because it is
not GPL'ed yet can only run when the GPL'ed runtime system is
used. This puts us directly into debian-legal's standing flamewar
about when something is a deriviative of something else, and what
the "mere aggregation" clause in GPL means.

The choice of QPL for the compiler is somewhat peculiar, given
that it is not related to Qt at all. It is concievable that the
author of Ocaml simply likes the QPL better than the GPL.

It is even more mysterious why the run-time system is GPL. It is
inherited from the Caml Light bytecode interpreter, but Caml Light
itself is not GPL'ed but distributed under a non-free licence
(distribution for profit is not allowed).

> Can I write software in Ocaml without requiring users
> get non-free software to compile it?

The software is not non-free, but it seems to be an open question
whether it is distributable at all.

It is also questionable whether the GPL-ness of the bytecode
interpreter contaminates the program it interprets. I cannot
imagine that anybody has meant it to be, but it would have been
nice to have a clear statement saying that the bytecode interpreter
can be distributed (under standard GPL permissions) together with
bytecode that is not itself GPL'ed.

Cc to the ocaml maintainer: Do you know the upstream author's
position about these issues?

-- 
Henning Makholm   "Der er ingen der sigter på slottet. D'herrer konger agter
                 at triumfere fra balkonen når de har slået hinanden ihjel."