Well, you could compile to native code instead.
Additionally you have,
- Avian (http://oss.readytalk.com/avian/)
- Codename One (http://www.codenameone.com/), just for mobiles
- Aonix (http://www.atego.com/products/aonix-perc/)
- WebSphere Real Time (http://www-03.ibm.com/software/products/us/en/real-time)
- Jikes RVM (http://jikesrvm.org/)
Well, you could compile to native code instead.