[nickpsecurity]

There's a lot of them:

https://en.wikipedia.org/wiki/Embedded_Java

A particular vendor (formerly Aonix) that always had interesting innovations in runtimes, tradeoffs, FFI's, and so on:

http://www.businesswire.com/news/home/20050307005203/en/Aoni...

https://www.ptc.com/developer-tools/perc

Each of them is a company making serious money in embedded systems. A few do safety-critical. I'll let you wonder whether they were in their right mind for building Java apps and using Java runtimes that don't seem to fail in high-stakes circumstances.