Today we enabled IonMonkey, our newest JavaScript JIT, in Firefox 18. IonMonkey is a huge step forward for our JavaScript performance and our compiler architecture. But also, it’s been a highly focused, year-long project on behalf of the IonMonkey team, and we’re super excited to see it land. SpiderMonkey has a storied history of just-in-time compilers. Throughout all of them, however, we’ve been
![IonMonkey in Firefox 18](https://cdn-ak-scissors.b.st-hatena.com/image/square/4b00eb5d34d32d5ece897d8330e30291e55eecb4/height=288;version=1;width=512/https%3A%2F%2Fblog.mozilla.org%2Fjavascript%2Ffiles%2F2012%2F09%2Fchart_1-300x185.png)