Is the LGPL applicable for applications?

Question

I am working on an application that will have support for plug-ins. I am wondering if I can apply the LGPL on the application, or is the LGPL only for libraries?

The main point is that I want the application to be roughly GPL, but that this is not enforced on plug-ins or scripts that the application loads. However, the GPL considers plug-ins to be derived works, so a pure GPL is not good in this case.

Currently I have been thinking about the MPL, but that explicitly states that the license will be under Californian jurisdiction, which for a European is not really acceptable.

What would the more prudent choice be for the license of the application be if I want a weak copy left. Are there any standard exceptions to the GPL that I should apply instead of the LGPL, and how does the LGPL apply to applications? The license does speak about libraries, which for me is rather confusing if I want to apply it on an application.

Answer 1

Yes, it can be applied to applications. LGPL3 is GPL + linking exception, so it should be suitable for your application. OpenOffice is an example of a big application that is LGPL, and I believe their reasoning was similar to yours.

Answer 2

LGPL should be fine for what you describe. As far as plugins are concerned, your application is the library, so to speak.

If you still want licenses that apply to individual files (making it possible to produce derived works - such as plugins - so long as they don't include any bits of the original files), you might also want to consider something like Microsoft Reciprocal License (it doesn't mention Microsoft in the text, so it's perfectly reusable):

Reciprocal Grants- For any file you distribute that contains code from the software (in source code or binary format), you must provide recipients the source code to that file along with a copy of this license, which license will govern that file. You may license other files that are entirely your own work and do not contain code from the software under any terms you choose.

So it's effectively like the MPL, but much shorter and clearer, and is not tied to a specific jurisdiction, with one exception:

The terms "reproduce," "reproduction," "derivative works," and "distribution" have the same meaning here as under U.S. copyright law.

But this is more of a clarification to reuse the existing definitions of the terms.

Answer 3

However, the GPL considers plug-ins to be derived works.

Only if they reuse code form the GPL part, you can have a propriety plugin to the linux kernel for example a closed source device driver.

Answer 4

One good reason for this is for letting people take some code from your application, stick it in a library and not forcing them to release the code o their application just because they are using "your code".

So IMHO - yes, LGPL is applicable for applications.