#ZipLib可以用于闭源软件

一直对各开源协议理解得不够透彻,对#ZipLib说的这段话:

[quote]
he library is released under the GPL with the following 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. 

[/quote]

一直没弄明白是怎么回事,什么样才算是"derived from or based on"? 到底是允许不允许私有非GPL的项目使用?

今天在它的论坛上发现了这样的回答:

[quote]

Yes, you can use the library in a closed source application. The license comes with an exception to the GPL which explicitly allows this.

However, you will need to link against the compiled assembly. Use and modification of the source code require you to publish your code under the same license.

[/quote]

原来只要不使用它的源代码,只是在编译和发布时链接它的dll,就可以对自己的代码选择自己的协议了--只要不违反你使用的任何其它组件的协议.

[Update]
看来他们也觉得有必要解释一下了.现在SharpZipLib首页有了以下说明:
Bottom line In plain English this means you can use this library in commercial closed-source applications.