Comments on: Why They’re Wrong: WordPress Plugins Shouldn’t Have to be GPL

By: Thomas Bodetti

Thomas Bodetti — Mon, 03 Jan 2011 22:50:32 +0000

I suspect that eventually this will get hauled into court, and perhaps we will have at least some legal definition, of course that will not settle the matter forever, until that time this is mostly speculation, subject to subjective subjection.

Software is perfectly capable to playing well together is it humans that seem to not be able to get along.

By: redwall_hp

redwall_hp — Mon, 02 Nov 2009 23:41:13 +0000

"So whatever the reason is wordpress.org does not allow non-GPL plugins, it is not because that is enforced by the GPL. Rather, it is automatic's deliberate decision to do so. And that's OK. Their website, their rules."

And I'm okay with that. The problem I have is that they're so vocal about other websites not following the same rules. They pressured theme authors to make the PHP portions of their themes GPL, and they're doing the same thing with plugins. The Thesis people are standing their ground so far, and I applaud them for that.

By: Hackadelic

Hackadelic — Mon, 02 Nov 2009 19:05:18 +0000

I think you are making the assumption that providing the plugin download is "redistributing". I think that's not quite true.

Be that as it may, the GPL does not prohibit SEPARATE distribution of copylefted with non-copylefted software. The explicitly allow putting such a mix on a single DVD and distributing that DVD. Similarly you are allowed to provide GPL-ed and non-GPL-ed stuff on the same website. (For example, donwload.com has all kinds of downloads, and they don't have to fear any license liability threats.)

The only legal problem would arise if they tried to package WordPress itself with non-GPL-ed plugins, but that's something they won't do w/o checking back w/ the plugin author (who then may copyleft the plugin for the sake of inclusion).

So whatever the reason is wordpress.org does not allow non-GPL plugins, it is not because that is enforced by the GPL. Rather, it is automatic's deliberate decision to do so. And that's OK. Their website, their rules.

By: redwall_hp

redwall_hp — Tue, 11 Aug 2009 23:19:14 +0000

That's certainly one way to put it.

By: Hackadelic

Hackadelic — Tue, 11 Aug 2009 09:55:48 +0000

Why not vote about this? [polldaddy 1862941 http://answers.polldaddy.com/poll/1862941/ polldaddy]

By: Hackadelic

Hackadelic — Tue, 11 Aug 2009 09:54:38 +0000

Furthermore, often it is even the other way arround: *WP calls the plugin* (hence the term "callback"). While the plugin does call WP functions to register it's callbacks, the *main* plugin functionality is invoked by WP. So even if calling a function *would* mean deriving work in the sense of GPL (however ridiculous it might be), it is then WP which "derives" from a plugin, not less than a plugin "derives" from WP.

By: lloydbudd

lloydbudd — Tue, 11 Aug 2009 07:43:00 +0000

The Linux Kernel isn't an analogous example for a number of reasons, the most striking being:

Linus Torvalds added an additional section to the Linux Kernel license that clarified that "This copyright does *not* cover user programs that use kernel services by normal system calls", but without that section that is not the interpretation of the GPL by the FSF as it applies to modules, and that is why the FSF also provide an LGPL license.
http://ftp.sunet.se/pub/os/Linux/kernels/COPYING” target=”_blank”>http://ftp.sunet.se/pub/os/Linux/kernels/COPYING

Your statement "That would mean a plugin would be a separate work, and would only have to be licensed under the GPL if it was distributed with WordPress itself." is close, but not quite right I think. Here is a clarified version:
That would mean a plugin would be a separate work, and would only have to be licensed under the GPL if it was distributed with WordPress *code*." Calls to WordPress functions is WordPress code. So, you can distribute (your code) the same code without the WordPress functions under any license you like — seems obvious, but that is what that legalize is describing explicitly.

By: Hackadelic

Hackadelic — Sun, 09 Aug 2009 00:27:31 +0000

For the sake of accuracy (even if I would have loved the argument): IMO Habari uses the Apache License, which is incompatible with GPL 2, hence they couldn't have required GPL for plugins. The Apache License, on the other hand, is much more liberal, and allows almost any mix of other license.

By: redwall_hp

redwall_hp — Sat, 08 Aug 2009 16:32:55 +0000

It would also imply that using a 3rd-party library (such as SimplePie, or one of many publicly-available PHP classes) makes your work derivative of theirs, which just *sounds* ridiculous.

By: Hackadelic

Hackadelic — Sat, 08 Aug 2009 12:41:13 +0000

Calling WP functions is essentially executing code, not deriving from it. You build every software in the context of some knowledge, and in case of WP plugins it is the knowledge about the WP API. That doesn't mean you derive your plugin's functionality from that of WordPress. That would be a ridiculous statement, no matter the lines of code. It would mean that interfacing with 3rd party software is "deriving" from it. Or that coding a PDF reader from scratch is work derived from Adobe's PDF code, just because you rely on the PDF format definition (which IS your interface in that case). Come on…