Re: [Ikvm-developers] OpenJDK licensing (boring!)

[Jeroen F. <je...@su...>]

Michael Kay wrote:
> It would be good to have a reference that says exactly what OpenJDK
> version you are distributing and what modifications you made, and a
> pointer to the license that you are relying on. I assume it is this:
>
> http://openjdk.java.net/legal/gplv2+ce.html
>
> but it would be nice to have confirmation.

Yes, that is correct. You can see the license referenced in the copyright version header of IKVM.OpenJDK.ClassLibrary.dll (on Windows, right click on the file -> Properties -> Details).

The version of OpenJDK that IKVM 0.36 is based on is OpenJDK 7 b13.

> One of the rules of this license is that when you redistribute GPL
> code, you must include or reference a copy of the license, and it's not
> clear to me currently how you are meeting that condition.

There is a LICENSE file in the root of the zip.

> Another rule is that each file you modify should include details of the
> modification.

I consider having a publicly accessible version control system as meeting this requirement.

> That obviously doesn't work when you jave modified binary
> files wholesale by converting them to CIL, but a top-level statement of
> how the code has been modified would be a good substitute.

I fail to see how such a statement would add any value, considering that all the source code (including the build process) is available.

> Also, in the downloaded code I see there is a directory called icedtea.
> Where does this fit into the picture? Does this have any separate
> license implications?

IcedTea is a GNU Classpath derivative. The parts of IcedTea I used are also licensed under the same conditions (GPL + Classpath exception).

> I think it would be also useful if you assert clearly that you consider
> parts of IKVM other than the Classpath library to be "identifiable
> sections of that work are not derived from the [GPL] Program, [that]
> can be reasonably considered independent and separate works in
> themselves" and therefore not infected by the GPL license.

The best way to ascertain this is to look at the copyright/license headers of the individual source files. However, for the files in ikvm/bin only ICSharpCode.SharpZipLib.dll and IKVM.OpenJDK.ClassLibrary.dll should be "infected" by the GPL.

Regards,
Jeroen