Back in the day I worked for a company whose J2ME engine was much faster than the competition, which was pretty much because it had a JIT and the competition wa

Back in the day I worked for a company whose J2ME engine was much faster than the competition, which was pretty much because it had a JIT and the competition was interpreted. (We also had our own homebrewed implementation of most of the Java libraries, which tended to be more efficient because they weren't written in Java.)