It"s no secret that Firefox, which was once the fastest browser out there, has begun falling behind in the JavaScript speed race. Browsers, like Google Chrome and Opera, now make Firefox seem sluggish by comparison. This doesn"t mean that Firefox is slow; but these days, a lot of attention is paid to milliseconds of load time, measured by JavaScript performance. As a general rule, the faster the JavaScript engine, the faster the browser.
Ars Technica sheds some light on the current situation and what Mozilla plans to do to regain its crown. Dubbed JägerMonkey, the upcoming JavaScript engine for Firefox is in the oven, and looking hot. As part of the engine, Mozilla is pulling code from Apple"s open-source Webkit. This, as well as Firefox"s current JavaScript engine, TraceMonkey, will be fused together into a whole new animal. Using Apple"s JSCore engine and its just-in-time (JIT) compilation, JägerMonkey could prove to be a serious competitor for the speed crown.
Here"s how Mozilla developer, David Mandelin, explains JägerMonkey:
"The reason we"re [building JägerMonkey] is that TraceMonkey is very fast for code that traces well, but for code that doesn"t trace, we"re stuck with the interpreter, which is not fast. The JägerMonkey method JIT will provide a much better performance baseline, and tracing will continue to speed us up on code where it applies."
Mozilla"s trace optimization has proven to significantly boost JavaScript speeds when compared to previous versions of their own JavaScript engines. Taking that speed boost and fusing it with JIT compilation will give Firefox the best of both worlds, and hopes to deliver the fastest web experience available. JägerMonkey is still in the earlier stages of development, and no ETA has been mentioned.