Google Writes JS Engine for Internet Explorer

The IE9 team published a video today showing what we can expect from IE9’s JavaScript when it launches.  No, Google didn’t actually write the code for their new JS Engine, but it sure spelled out the roadmap.  In the video, the engineers talk candidly about their new engine, from copying V8’s JIT and polymorphic inline caching, to copying V8’s irrexp optimized regular expression library.  They even politely acknowledge that Chrome is “doing a really good job”.

In the video, IE9 is still quite a bit slower than Chrome.  But it is fantastically superior to IE8.

The great thing about this is that competition works.  Microsoft had the opportunity, but didn’t significantly improve their JS engine performance for the last 10 years.  It took Google Chrome, what Ballmer calls a “rounding error” to finally make Microsoft improve in this area.  In a few years, whether you pick IE or Chrome or Firefox as your browser, rest assured your browser is fast because of competition.