If a JavaScript function is called more than six times, or loops more than 100 times, it gets fed into the next stage: a basic JIT compiler that produces executable code.

Both were introduced three years ago as a part of a two-tier compiler system. Ignition is a bytecode interpreter whose job is to start executing the JavaScript with as little delay as possible.

anguyen asks:. The first compiler was written by Grace Hopper in 1952 while the Lisp interpreter was written in 1958 by John McCarthy's student Steve Russell.