Apache Harmony

Apache want to create/obtain a Java VM of their very own. I've always thought about doing something like this, but that's another story. This post is about modularity in a virtual machine.

I suggested somewhere in the mailing lists that the JIT compiler could be used as the basis for writing the VM in Java. It's quite simple: the JIT converts bytecodes to native, so why not use that as the way to convert the bytecodes of a java application (the VM) into native as a one-off compilation stage. The one difficulty is memory management, but let's assume this can be overcome with some basic conventions when writing the VM.