Altering open source code

Question

Assume that I am using an open source jar file in my project which is of size 11mb. But I am not utilizing this jar fully (I'll never utilize in the future too). I know that I just need couple of classes from this jar which does my job. In such case, can I just delete the other classes in the jar file and use it?

I'll make sure that whatever the classes remain in the jar is complete by itself. Meaning, these classes do not depend on any other classes in the jar. So Can I just remove the unwanted classes in the jar so that the jar file gets reduced? If I do this job, it it legal? Am I allowed to do such stuff and use in my project?

Answer 1

SmartGWT appears to use the LGPL licence . This means you can link to it even in a proprietary closed-source application without the need to release your source code if you distribute it.

However, this freedom may not apply if you modify the library.

A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License.

It could be argued that chopping out bits of the library creates a derivative work even though you've not altered the source code itself, but IANAL.

Of course, if you are not distributing your project (for example, it's an internal business application for your company) then I don't believe the requirement to release your source code applies even with a derivative work.