Major JavaScript Enhancements Make Firefox Speedy – up to 30% Faster
Firefox for Windows, Mac and Linux has new JavaScript enhancements that make Web browsing significantly faster. The latest update to Firefox includes Type Inference which boosts JavaScript performance and allow rich websites and Web apps with lots of pictures, videos, games and 3D graphics to load and run much faster. Type Inference is a feature of the SpiderMonkey JavaScript engine that integrates with the JaegerMonkey JIT compiler to provide analysis and help generate more efficient code. Firefox with Type Inference is up to 30% speedier on JavaScript benchmarks like Kraken and V8.
Last Release in 2011, More to Come Next Year!
Source: http://blog.mozilla.com/blog