[kaffe] Can Kaffe profit from the released JDK in Sun's SCSL?

Dalibor Topic robilad at yahoo.com
Fri Jun 20 08:13:01 PDT 2003

--- Mario Smit <mario.smit at hccnet.nl> wrote:
> Hi all,
> Kaffe was developed mainly as an open-source alternative of the (at that
> time) proprietary JDK of Sun.

It still is proprietary, actually.

> Starting from the 1st quarter of this year SUN released the JDK as part of
> the SCSL initiative. Included is the source code of the Hotspot VM, the
> whole class-path of Java 1.4.1, etc.

They have published the source code for their VM earlier as well, under not
very liberal licenses. Contributors to kaffe have always been advised to stay
away from Sun's source code, since that would make them 'tainted' and open up a
can of worms for a clean-room effort like kaffe.
> Of course this initiative comes years too late. But are there intentions to
> use (parts of) Sun's version in Kaffe? I mean the Kaffe VM with Sun's own
> class-path?

Unless Sun changes their licensing to be GPL compatible, don't touch their
sources with a flagpole. Here's the relevant bit from the JINI (also available
under SCSL) licensing FAQ ( http://www.jini.org/process/lic_faq.html )

9. Can I create new code from a combination SCSL covered code and code covered
under a different license?

      This depends on the other license. The SCSL does not forbid such
intermingling, but the terms of other licenses may be incompatible with the
terms of SCSL. For example, GPL's "viral" nature requires that any modified GPL
code be itself redistributed under GPL. If you mixed GPL code with SCSL code,
the GPL would require you to redistribute the mixed code, including the SCSL
code, under GPL, which is not allowed.

> This way you can concentrate on the VM and don't have to re-create all the
> libraries, like Swing, etc.

That's the theory. How much of an effort it would take to get kaffe to work
with  Sun's library code is on a different sheet of paper. Their internal
representations will differ quite a bit from kaffe's, so I assume re-using
sun's hotspot, for example, would require a major rewrite of kaffe's internals
to match the expected structures. Reusing the library code is always an option,
* when * they get cool enough to release it under a GPL compatible license.
Knowing how bad Sun has been burned by the Java-fork from Microsoft, I assume
the only way that's ever going to happen is when Sun is acquired by RedHat,
SuSE or Mandrake, and that's very, very unlikely ;)

Anyway, I'm planning to slowly move kaffe's libraries into direction of GNU
Classpath, so that kaffe can profit from the magnificant work done by Classpath
hackers. We also have bits of class library from other third parties in kaffe,
and we're trying to be as complete as it gets in the free software java
libraries world in the long run. And we could always use a hand or two ;)

> Or is it legally not possible to mix SCSL and GPL code?

Not possible.
> I would like to hear your opinions.

Sun's offer is like a poisoned apple ;)

dalibor topic

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