getting started with classpath

[Phillip Morelock]

Hello I'm seeking "getting started" help.

I have a gnawing interest in hacking on classpath, and I have read 
a couple of times over the guide "hacking.html" that is linked from 
the GNU site.  It's just, I'm having a simultaneous-learning-curve 
experience, and I'm wondering if anyone on this list can push me 
off in the right direction to eventually being able to contribute.


My "problems" or rather questions are as follows:
1.  I only have experience using one JDK/JRE (Sun's), although I 
have used it on many platforms.  I noticed a strong linkage between 
Classpath and (of course) the free JVM / compiler implementations.
That's cool, I get it, I am just not sure which components each 
of these tools replace, and what their level of compliance / implementation 
is.  Is there maybe a best order to learn about these tools in?  
I would like to know Free Java and work on it even, but am not sure 
how to start.

2.  How can I be certain I meet the "clean room" requirement?  I 
have browsed through several of sun's classes several times in source 
code form as included on my Mac OS X machine.  I know that I don't 
remember any specifics, they were just instructive at the time.  
Does this count?

3. If I write "pure java" implementations, do I need to worry much 
about your notes on native code and VM integration?  I have not done 
any JNI programming, but I am okay with learning.  I guess, a better 
question is, what is the view of this project as far as native code,
VM integration, etc.?  I get the feeling by browsing the classes 
that there isn't much native code in the non-GUI components.

Any "getting started" tips would be much appreciated -- it seems 
like there's a lot to learn for someone coming from a pure Sun world 
as far as the raw implementation goes.

Cheers
Phillip