Re: [libreplanet-discuss] Licensing '?'

[Joshua Gay]

On 03/31/2016 05:12 AM, Julien Kyou wrote:
> I've never really been sure how licensing / relicensing work. I am
> trying to figure out first: what it means for a license to be GPL
> compatible (because I think I'm misunderstanding); 

A while back I wrote an elementary explanation of copyright and
licensing for a friend. It's a little long but it might be useful. I put
it here <https://libreplanet.org/wiki/User:Jgay/Copyright-license-note>.
You can also find links to various educational licensing materials we
have published at <http://www.fsf.org/licensing>.

> second: is Apache 2
> compatible with v3. According to a third party (.. can''t remember who
> sorry), FSF says no but Apache says yes. And third: if I fork something,
> then modify it, do I now have the authority to copyleft it as I wish or
> can compatibility bite me.

The FSF maintains a list of various licenses and comments about them. On
this list we indicate whether or not a license is compatible with the
GPL and/or a particular version of the GPL. Our entry for Apache 2,
<http://www.gnu.org/licenses/license-list.html#apache2>, states:

This is a free software license, compatible with version 3 of the GNU GPL.
    Please note that this license is not compatible with GPL version 2,
because it has some requirements that are not in that GPL version. These
include certain patent termination and indemnification provisions. The
patent termination provision is a good thing, which is why we recommend
the Apache 2.0 license for substantial programs over other lax
permissive licenses.


-- 
Joshua Gay
Licensing & Compliance Manager  <http://www.fsf.org/licensing>
Free Software Foundation        <https://donate.fsf.org>
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