GNU Java vs. Sun Java: What's the difference, what is better?

Dotan Cohen dotancohen at
Thu Dec 28 12:39:07 UTC 2006

On 28/12/06, Gilles Gravier <Gilles at> wrote:
> Dotan,
> Java isn't just a language... it's a platform. If it was only a
> language, you'd be stuck with having to compile it for a specific target
> environment / CPU / OS... but since it's a complete platform, that
> includes the specifications of a very well defined execution
> environment, when you compile your Java source, the resulting bytecode
> is capable of running on any machine that has the proper runtime
> environment.

Er, so now I've been proven a normal computer user: even I didn't know
correctly what Java is! Thank you for the correction.

> Now this is where it gets complicated... some runtime environments don't
> run all Java applications. For example, take something that does a lot
> of fancy things, like AppGate's MindTerm SSH applet/application (you can
> download it - sources and binaries - from
> ) run nicely in
> any of Sun's Java runtimes (at least anything above version 1.2)... But
> fails to run on GNU Java. I must say I haven't investigated completely,
> but my guess is that either GNU Java implements some classes differently
> than the spec says... or doesn't implement all the classes.

That would make it not a "proper" runtime environment, as per your
previous paragraph.

> In any case (and particularly now that we've open-sourced it) I
> recommend going for Java 1.6 from Sun
> (, either in source
> form... or in binary form. In any case, it's GPLed and will fit nicely
> next to a Linux kernel.

Excellent. Say "thank you" to yourself and your coworkers on my
behalf. Great work.

> Gilles (caveat : I work for Sun - Gilles.Gravier at

Yep, the previous paragraph gave that away!

Dotan Cohen

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