From: Chad Perrin <perrin@...>
Date: 2007-10-15T04:00:27+09:00
Subject: Re: MIT vs. Ruby/GPL License

On Mon, Oct 15, 2007 at 02:50:29AM +0900, Trans wrote:
> 
> Kind of fuzzy.

My understanding is that a gem distributed under the terms of the GPL
then causes the program in which you use it via a `require` statement to
be subject to the terms of the GPL as well.  This is, for an interpreted
program such as one using the reference implementation of Ruby, roughly
equivalent to a statically linked library in a binary compiled program
written in C -- where the GPL would certainly apply to the whole program
if the library were distributed under the terms of the GPL.

On the other hand, the source *without the library* could be distributed
under whatever other license you like.  If it were distributed under a
license with which the GPL is not compatible, however, anyone who
received it would then not be able to compile it with the GPLed library
statically linked and subsequently distribute it, since the terms of the
GPL and those of the other license you used would be in direct legal
conflict with one another.

Moral of the story -- don't license your code under the CDDL if it
requires a GPLed library and you want people to be able to compile and
redistribute the software (such as via the software management system of
a Linux distribution or BSD Unix OS) legally.  I won't comment for the
moment on the wisdom of using the BSD license, the CDDL, or the GPL, in
and of themselves, because this is ruby-talk and flame wars are bad.

Disclaimer: I am not a lawyer.  I just think about stuff like this a lot.

-- 
CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
Patrick J. LoPresti: "Emacs has been replaced by a shell script which 1)
Generates a syslog message at level LOG_EMERG; 2) reduces the user's disk
quota by 100K; and 3) RUNS ED!!!!!!"