LGPL is Viral for Java

carlfish writes "According to this post to POI-dev, Dave Turner (Mr License) of the FSF has decreed that the steps required to use an LGPL'd Java library will actually infect client code with substantial GNU-ness via Section 6 of the LGPL. (The "Lesser" GPL is supposed to protect only the Library, without infecting code using the library) This, as you might imagine, puts a few LGPL Java projects that previously thought they were embeddable without being viral in a bit of a bind. Various weblogs have further coverage." Update: 07/18 02:44 GMT by CN : The FSF's Executive Director, Brad Kuhn adds "LGPL's S. 6 allows you to make new works that link with the LGPL'ed code, and license them any way you see fit. Only the LGPL'ed code itself must remain Free. Such 'client code' can even be proprietary; it need not be LGPL'ed."

Comments

Misleading article

[timsuth]

This slashdot article is misleading. It gives the impression that if your Java code uses an LGPL library then you must provide your source code, permit changes/redistribution etc.

This is not the case. What the FSF guy way saying is "With respect to the LGPL, 'import' in Java is equivalent to linking in C." This means that if you make changes to an LGPL library you use via import in Java, you must make the changes to the LGPL library available to others. This is exactly the same situation which applies in the C world.

The reason the Apache people don't want to use the LGPL (for any language) is that they want their libraries to be under a more permissive license which allows the libraries to be modified without requiring the users to make the changes available.

Some people were suggesting that there was a loophole in the LGPL which meant that they could 'import' a library in Java and avoid having to make changes to the LGPL library available.

The "news" is that the loophole does not exist - the LGPL applies to Java in the same way as it does in C.

Yes, that David Turner

[prizog]

Hi. I'm that David Turner who is quoted. I'm not the David Turner who works for Microsoft, and I do not hack on Freetype.

First, I'm upset that CowboyNeal didn't contact me -- as the article says, I work at the Free Software Foundation, and you can find our phone number on our web page by searching for "s" on Google and clicking "I Feel Lucky."

Now, if you read section 6 of the LGPL, it's not the same hereditary [1] thing as section 2 of the GPL -- what it says is that your program, which links against the library, does not need to be licensed under the LGPL. But you do have some obligations -- you need to allow people to relink your code with new versions of the library.

[1] I think hereditary is a much better analogy than viral, and I thank the person who came up with it and whose name I forget.

Re:Yes, that David Turner

[prizog]

Oh, wait, now I actually read your post, and realize that you are still completely confused. Sorry.

Let me make it clear: Section 6 is not what you think it is.

You think section 6 says:

You must cause any work that you distribute or publish, that links to the Library, to be licensed as a whole at no charge to all third parties under the terms of this License.

Section 6 actually says: ...distribute that work under terms of your choice, provided that the terms permit modification of the work for the customer's own use and reverse engineering for debugging such modifications.

Note that this does not require the provision of source code, nor does it require allowing the original program or modifications thereof to be distributed.