MySQL’s license is GPL. ActiveRecord, which (I presume) uses MySQL’s
client libraries, is under the MIT license. How does ActiveRecord
avoid being GPL?
On Mon, Mar 21, 2011 at 1:48 PM, Paul E. G. Lynch
[email protected]wrote:
MySQL’s license is GPL. ActiveRecord, which (I presume) uses MySQL’s
client libraries, is under the MIT license. How does ActiveRecord
avoid being GPL?
I’m no attorney but I believe the answer is that ActiveRecord is not
modifying MySQL but is a separate framework for accessing it as well as
a
number of other databases. You still need a copy of MySQL if you want to
use
the part that can access it. The FAQ for GPL/GNU explains more in the
section on “Using programs released under the GNU licenses when writing
other programs”.
http://www.gnu.org/licenses/gpl-faq.html
B.
GPL requires that if you link with the library, you have to have a GPL-
compatible license so that the result is available under GPL. See:
http://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL
So, if ActiveRecord is linking with the MySQL libraries, then my
understanding is that it should be GPL (or something compatible).
Just to clarify, I do not wish ActiveRecord to be GPL, and I do not
even like GPL. I am just trying to understand how they have avoided
that license issue, because it has implications for the Ruby on Rails
web application I am working on (for which we are working on a
license).
--Paul
On 21 March 2011 18:48, Paul E. G. Lynch [email protected] wrote:
MySQL’s license is GPL. ActiveRecord, which (I presume) uses MySQL’s
client libraries, is under the MIT license. How does ActiveRecord
avoid being GPL?
Oracle makes an exception to the GPL for MySQL which (loosely
paraphrasing) allows linking the MySQL client libraries with non-GPL’d
software, as long as that software is licensed under another approved
FOSS license:
http://www.mysql.com/about/legal/licensing/foss-exception/
Chris
On Mar 21, 8:05pm, “Paul E. G. Lynch” [email protected] wrote:
My reading of http://www.mysql.com/about/legal/licensing/foss-exception/
is that there is an exception for linking with the mysql libraries, as
long as the work produced is under one of many licenses (including the
mit license, which is the license under which rails is distributed if
my memory is correct).
That said, activerecord doesn’t link to any native libraries. If you
use the mysql adapter, that pulls in the mysql gem, which does
obviously load the mysql library, but if you don’t use mysql then that
will never happen. Don’t ask me what the legal implications are!
Fred
On Mon, Mar 21, 2011 at 3:05 PM, Paul E. G. Lynch
[email protected]wrote:
license).
–Paul
According to the MIT License it is compatible with GPL (
MIT License - Wikipedia). There is more links in there
to
how the compatiblity works. To my knowledge no one has had a legal issue
yet
with connecting their Rails app through ActiveRecord to MySQL. I hope
that
helps.
B.
On Mar 21, 4:46pm, Frederick C. [email protected]
wrote:
On Mar 21, 8:05pm, “Paul E. G. Lynch” [email protected] wrote:
That said, activerecord doesn’t link to any native libraries. If you
use the mysql adapter, that pulls in the mysql gem, which does
obviously load the mysql library, but if you don’t use mysql then that
will never happen. Don’t ask me what the legal implications are!
You are right. I should have been asking about the MySQL gem, instead
of ActiveRecord. The MySQL gem is licensed under the Ruby license,
but links with the MySQL client libraries, and so (if I am correct)
should be GPL instead. But, if that becomes GPL, then it would infect
ActiveRecord, and so we are back to my original question. I would be
delighted to find that I am wrong about that.
–Paul
On 21 Mar 2011, at 20:33, Bryan C. wrote:
that license issue, because it has implications for the Ruby on Rails
helps.
License compatibility isn’t bi-directional.
“MIT is compatible with GPL” means that you can link to or include an
MIT-licensed library in your project, and then license your project (the
combination of your work and the MIT-licensed library) under the GPL.
However, because of the viral nature of the GPL, you cannot link to
GPL’d code in your project and then license your project under the MIT
license. This is only possible if the copyright holder of the GPL’d code
grants you an additional license (which is the case with the MySQL
client library).
Chris