In the late 2000s, major browser developers engaged in a "race" to develop faster JavaScript engines in response to growing JavaScript usage on websites. Initially praised for its performance, Google Chrome's engine was later outperformed by WebKit's Squirrelfish and Mozilla's TraceMonkey. Google responded with the V8 engine, boosting Chrome's speed. By 2010, browsers like Safari, Firefox, and Opera incorporated new engines like Nitro, JägerMonkey and Carakan, improving JavaScript performance. However, Microsoft still lagged behind with Internet Explorer lacking a dedicated engine.

1. JavaScript engines
performance comparison

2. The JavaScript engine race:
2008 and 2009
Recently there has been a race by browser
developers to develop even faster JavaScript
engines in response to the growing usage of
javascript frameworks and ajax, as the
user's experience is directly influenced by
the browser's ability to execute the site's
client-side code.

3. In 2008, Google Chrome was praised for its
JavaScript performance, but other browsers
soon received new JavaScript engines which
were faster. Later, Google Chrome won in
the races of better performance. Chrome's
strength is its application performance and
JavaScript processing speed, both of which
were independently verified by multiple
websites to be the fastest amongst the major
browsers of its time.

4. With the advent of WebKit's Squirrelfish
and Mozilla's TraceMonkey JavaScript
virtual machines, Chrome's JavaScript
execution performance has been found to be
slower.Google responded with the Danish
developed V8 which boosted JS
performance in Google Chrome 2.

5. On June 2, 2008 the WebKit development
team announced SquirrelFish, a then-new
JavaScript engine that vastly improves
Safari's speed at interpreting scripts. The
engine was one of the new features in Safari
4, released for developers on June 11, 2008
the final JavaScript engine was called Nitro.

6. In January 2009 the engine then known as
SquirrelFish Extreme (SFX) was enabled for
Mac OS X on x86-64 architectures as it
passes all tests on that platform by Apple
Inc.[12] Released June 30, 2009 Firefox 3.5
includes the optimization technique which
offered "performance improvements
ranging between 20 and 40 times faster"
compared to Firefox 3 in some cases.

7. The JavaScript engine race: 2010
In early 2010 the Norwegian Opera browser
replaced the aging Futhark with the faster
Carakan, which was 2.5 times faster in early
testing Others in the race at this time
include Apple's Safari's Nitro (the engine
formerly known as SquirrelFish), and
Firefox's new JägerMonkey (a "cross-child
of Nitro with the older TraceMonkey
Engine").

8. Microsoft lagged behind, lacking a
dedicated JavaScript engine and being the
slowest of the major browsers, although by
mid-2010 they held out the carrot of Chakra
in then unreleased Internet Explorer 9.
JägerMonkey began testing in the publicly
released Firefox 4.0 beta in the Summer of
2010. Safari 5, also released in summer
2010, featured 30 percent faster JavaScript
performance than Safari 4 (using the Nitro
engine).