Наиболее впечатляющая Жаба для встроенных применений из всех, которые мне встречались:
http://www.rtjcom.com/main.php?p=homeIn contrast to other embedded implementations of the virtual machine the simpleRTJ requires on average about 18-24KB of code memory to run.
The simpleRTJ has been primarily designed to run on the small 8/16 bit systems with a small amount of memory. However, the simpleRTJ can also be used on the more powerful devices based on the 32 bit microcontrollers as it supports linear memory addressing of up to 16MB. Porting the simpleRTJ is quite straightforward and in some cases the compilation for the target device may not require any changes at all to the generic VM sources.
The simpleRTJ has been ported to a number of target processors including MC68302, MC68376/332, 68HC11, 68HC16, 8051XA, various ARM7/9 derivatives, H8S/2241, STi5512, embedded x86, ZSP200/400/neo, and many others.
The simpleRTJ includes all of the core features expected from any virtual machine like multi threading, exception handling, interfaces and the garbage collection. On top of this the simpleRTJ doesn't require any support from the underlying RTOS. In fact, it can be considered as a mini Java OS that can run on it's own as it has built in support for the memory allocation, heap management, multi-threading, software timers, etc.
The simpleRTJ is provided free of charge under the RTJ Computing non-commercial source code license agreement to everyone for evaluation, educational and private use.