What is leJOS?
leJOS (pronounced like the Spanish word "lejos" for "far") is a tiny Java Virtual Machine. In 2006 it was ported to the LEGO NXT brick.

leJOS NXJ includes all the classes in the NXJ API as well as the tools used to upload code to the NXT brick.

leJOS NXJ offers the following:

• Object oriented language (Java)
• Preemptive threads (tasks)
• Arrays, including multi-dimensional
• Recursion
• Synchronization
• Exceptions
• Java types including float, long, and String
• Most of the java.lang, java.util and java.io classes
• A Well-documented Robotics API