Mozilla claims Firefox 4 will have superior JavaScript performance

Mozilla director of web platform Chris Blizzard claims the JavaScript performance of Firefox 4 will be "one generation" ahead of all other browsers.

The open source outfit is working to enhance the Firefox JavaScript engine via a new extension dubbed JägerMonkey. With the debut of Firefox 3.5 last year, Mozilla significantly juiced JavaScript performance with a "tracing" compiler known as TraceMonkey, but not all JavaScript code is suited to this technique, which works to convert code loops into speedy assembly language. JägerMonkey aims to improve performance when tracing doesn't apply.

"What we've seen is that in places where our Tracing-Engine gets used we are actually faster than anyone else, it's just in those cases where it doesn't fit that others do a lot better," Blizzard told derstandard.at during an interview at a Linux desktop conference in the Netherlands. "So we're trying to improve our baseline performance and combine that with the Tracing-JIT, with this we'll be one generation ahead of everyone else."

Additionally, Blizzard also claimed that the performance differences between current-gen JavaScript engines are very small, and he questioned the reliability of JavaScript benchmarks, stating that the numbers are mostly not influenced by real JavaScript performance anymore.