node.js is the new java

it greatly improves on it's predecessors
familiar syntax
it's designed to be practical, to the chagrin of CS purists
next-generation of applications being built (hadoop, palantir, runsecape :  asana, meteor)

>>55

there are things that lua can do that javascript cannot, and places lua can fit in better than javascript would. It would be silly to use javascript for some of the applications that use lua for the same reason it would be silly to use lua for client side web scripting.