Redmond is targeting real-world applications based on real-world data. For example, every single JavaScript and DOM API used by the top 7,000 websites was recorded. IE9 will deliver support for every API used by those sites.

To speed up the JägerMonkey JavaScript engine.

A ridiculously useful JavaScript bookmarklet.

Shortwave responds to commands. A command consists of a predefined trigger plus optional search terms. To search Wikipedia for “bookmarklet” you would type w bookmarklet into the prompt and hit enter.

A quick and dirty “getting started” tutorial.

Chrome has substantially better JavaScript performance than Safari on my machine.

Chrome beta (full report)

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Total:                  601.2ms +/- 5.6%
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Safari 4 (full report)

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Total:                  699.0ms +/- 2.5%
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Significant improvements across nearly all test cases.