The JavaScript engine in Google’s Android 2.2 running on a Nexus One phone soundly spanks Apple’s iOS 4 incarnation running on an iPhone 4.
When running the industry-standard SunSpider benchmark (which you can run here), Android 2.2 was nearly twice as fast as Apple’s offering.
And learn more About Mozilla’s FireFox 4….not as fast as Chrome 5 or Safari 5, but the addons are so popular that speed isn’t everything.