RFC, Project Metropolis`

Andrew Dinn adinn at redhat.com
Mon Sep 18 14:05:34 UTC 2017

Hi John,

On 14/09/17 06:08, John Rose wrote:
> <http://cr.openjdk.java.net/~jrose/metropolis/Metropolis-Proposal.html>
> I would like to invite discussion on a proposal for a new OpenJDK
> Project[1], to be titled “Project Metropolis”, an incubator for
> experimenting with advanced JVM implementation
> techniques. Specifically, we wish to re-implement significant parts of
> Hotspot’s C++ runtime in Java itself, a move we call Java-on-Java.
Please don't take the the following as representing an answer from Red
Hat. With that qualification out of the way, I can say that am
personally very interested in contributing to a Java-on-Java OpenJDK
runtime -- having experienced many of the benefits of such a model
working on the JikesRVM and Xerox Interlisp-D runtimes.

This idea has many benefits, as you mentioned. I think it is
particularly valuable that a Java-on-Java implementation replaces the
hard, black box that currently separates VM tech from JDK tech with a
much more fluid, transparent boundary layer. The more that those who use
the JVM can understand about what it does for them and at what cost the

So, this gets a very excited thumbs up from me!


Andrew Dinn
Senior Principal Software Engineer
Red Hat UK Ltd
Registered in England and Wales under Company Registration No. 03798903
Directors: Michael Cunningham, Michael ("Mike") O'Neill, Eric Shander

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