[wp-hackers] Apache 2.0 License?

[Mark Jaquith]

On Sat, Mar 19, 2011 at 2:47 PM, Mike Schinkel
<mikeschinkel at newclarity.net> wrote:
> This question[1] got me thinking. It seems that excanvas[2] is becoming a standard dependency for Javascript charting libraries but it is licensed with Apache 2.0, not GPL 2.
>
> The core question I'm asking is would a plugin that is otherwise GPL licensed be denied inclusion into the WordPress plugin repository if it includes excanvas because of the Apache 2.0 license? Or given the circumstances would the potential license conflicts be overlooked?

Official answer: As Pete pointed out, The Apache 2.0 license is not
compatible with the GPL version 2. So that does not meet the current
licensing criterion, which is that the license be compatible with the
GPL version 2.

I'm still deliberating about whether to relax that criterion to allow
GPLv3-only or GPLv3+ (or compatible) code. We're already in the
situation where some plugin directory code is GPLv2-only instead of
GPLv2+, so combining that plugin code with WordPress already requires
care.

If you're writing a plugin, and are able to, I strongly urge to to
license it as "GPLv2 or any later version" (GPLv2+) or just as "GPL,
any version," as that allows for maximum flexibility.

-- 
Mark Jaquith