J2ME was an alphabet soup of incompatible implementations stuck somewhere between Java 1.2 and 1.3. Getting code to run across device manufacturers was a huge engineering burden. In fact doing something like JetPack for that world would be technically impossible.

If Sun was offering some technically relevant foundation for the smartphone era, it would have been able to actually have some adoption. They were starting from a leading position (obviously - see blackberry or Nokia), and in the space of 3 to 4 years they completely disappeared.

> J2ME was an alphabet soup of incompatible implementations

So Google?

(alphabet)