License for Open-Source Software w/ Plugins?

ThiagoHP asks: "I have developed MultiMAD, a rapid application development and prototyping for for mobile devices in my master's course, and now I want to share it with the community. It's written in Java and it has a plugin architecture in order to support different mobile device platforms (WAP, J2ME, PalmOS, etc). I want to give the freedom to anybody write their plugins, even closed-source, as long as the tool itself is not modified for them to run. This implies that GPL cannot be used. At the same time, I do not want any closed-source tool based in MultiMAD code, so licenses such as the Apache one cannot be used. Am I right in my assumptions regarding licenses? What license do you suggest?"

Comments

LGPL

[A.K.A_Magnet]

That's exactly what the LGPL is for.

Derivative of your code will be in LGPL, but code linked to it (as plugins or using it as a library) have no license requirement.

Check it out

Re:LGPL

[NotoriousQ]

Even better is to split the program into two parts. LGPL the core, and GPL the interface.

That or

[hummassa]

license your code under the GPL, and grant an additional exception that plugins can be proprietary. It would work, too... supposing the GPL really forbids dynlinking to proprietary modules, which is disputed.

It's not a GPL variant.

[hummassa]

Linux is a massively complex work when the subject is copyright. Basically, the kernel as a whole is GPLv2, and Linus (who has the copyright on a lot of code and has indirect copyright on almost the whole kernel [much kernel code which is not his is still derivative on his original linux v0.01]) says he -- like other intelligent people -- do not consider the FSF GPL FAQ as correct about linking (especially dynalinking) and the GPL.
IOW: when you GPLv2 some code, you are probably granting the right to dynalink proprietary modules to your work. Linus only stated this explicitly, thus estopping himself from suing anyone (nVidia?) who makes proprietary loadable kernel modules.

Yes you can...

[joto]

Here's how you word it:

This software is licensed under the General Public License (GPL), version 2 (see below for the full text of this license). As a special exemption, software plugins using the documented plugin API for this software, will be allowed to be distributed and/or run-time linked with this software regardless of their license.

[Explain the plugin API, or where to find the "documented" parts of it]

[Full text of GPL]

Just don't sue people who write closed plugins

[Anonymous Coward]

Uhm, the GPL doesn't control your app, YOU do. Here's what you can do.

#1) place the GPL in a file called "GPL".

#2) Place the following text in a file called "COPYING":

This program is copyright XYZ and can be distributed under the terms of the GPL (see the file "GPL") plus the following exception: any plugins written for this application are expressly exempt from any obligations required by the GPL. You must include this entire paragraph in any copies you make of this application.

Jeezuz people, it's YOUR application, you can license it any way you want! You can make it GPL on Tuesdays and MIT on Saturdays. This isn't rocket science, RMS doesn't control your app, you don't assign copyright to the FSF, a little bearded man doesn't pop out of your screen if you choose not to sue people who make closed-source plugins. The GPL doesn't enforce your copyright, YOU DO!