While proprietary and not very open to (or usable at all by...) hobbyists, ARMs Jazelle[1] is listed there at the bottom:

> The most prominent use of Jazelle DBX is by manufacturers of mobile phones to increase the execution speed of Java ME games and applications. A Jazelle-aware Java Virtual Machine (JVM) will attempt to run Java bytecodes in hardware, while returning to the software for more complicated, or lesser-used bytecode operations. ARM claims that approximately 95% of bytecode in typical program usage ends up being directly processed in the hardware.

Jazelle seems to be "old news" now though, replaced by something else.

While not the same thing as a hardware Java implementation, JavaCard[2] is pretty interesting. It's quite a bit different from "big" Java (especially the language features available), but it's very widely adopted in mobile phone SIM cards and traditional smart cards. I've got a yubikey neo here which is a JavaCard smartcard intentionally left very open to experimentation (the keys needed to manage the card and upload new applets aren't secret). I've uploaded applets to it on my own, both the OpenPGP applet and some simple stuff I wrote to play around.

[1]http://en.m.wikipedia.org/wiki/Jazelle

[2]http://en.m.wikipedia.org/wiki/Java_Card

That was a bit different as they were trying to replicate the JVM in hardware (i.e. as an instruction set). This is just a rewrite of python that can run on a small ARM chip. Still very impressive mind, but a different beast. It is more similar to .net Micro Framwork ( http://www.netmf.com/ ) .

There are small JVMs that are well suited to doing this. As a matter of fact ST sells a developer kit based on the exact same microcontroller series used here, the STM32F4 ( http://www.st.com/web/catalog/tools/FM147/CL1794/SC961/SS153... ) of course it comes with rather crippling limitations of 3 month eval time, and 1 hour run. It is obviously aimed at a rather different market though.