As far as I understand, the GPL is a license with an incredibly strong copyleft trait. That is, anything that even links to it, let alone modify it, needs to be released under the GPL. Due to this 'viral' nature of the license, some people and organizations have made exceptions. One notable one is the class path exception:

Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination.

As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

From what I understand, the GPL now allows people to link to the library without being forced to make their own works under the GPL. Hmm... Sounds awfully like the LGPL!

So then what difference is their between the GPL + class path exception and the LGPL? As far as I can tell, there isn't a difference. But surely, with the author of both licenses being the Free Software Foundation, you would think otherwise. Why would a license author create two different licenses that can provide the exact same thing? Aren't they just adding to the proliferation issue?


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