Mozilla answers Google's Crankshaft with IonMonkey
"Plenty to do after Firefox 4 comes out," Mandelin said . "In the words of David Anderson, 'The game’s back on'."
Crankshaft was inspired by Sun's Java HotSpot performance engine, the revamped Java virtual machine that arrived in 1999, according to an exchange between The Register and Google engineer Eric Kay in December. Google Chrome developer Lars Bak was the lead man on the Sun HotSpot team, and Crankshaft uses HotSpot-like "adaptive compilation", identifying important code and optimizing that code as needed.
Mozilla intends to share all its IonMonkey code across the x86, x64, and ARM platforms. ®