Internet Explorer 9

Internet Explorer 9 was released on March 14, 2011. Development for Internet Explorer 9 began shortly after the release of Internet Explorer 8. 

Microsoft first announced Internet Explorer 9 at PDC 2009, and spoke mainly about how it takes advantage of hardware acceleration in DirectX to improve the performance of web applications and quality of web typography. 

At MIX 10, Microsoft showed and publicly released the first Platform Preview for Internet Explorer 9, a frame for IE9’s engine not containing any UI of the browser. 

Leading up to the release of the final browser, Microsoft released updated platform previews, each featuring improved JavaScript compiling (32-bit version), improved scores on the Acid3 test, as well as additional HTML5 standards support, approximately every 6 weeks. 

Ultimately, eight platform previews were released. The first public beta was released at a special event in San Francisco, which was themed around "the beauty of the web". 

The release candidate was released on February 10, 2011, and featured improved performance, refinements to the UI, and further standards support. 

The final version was released during the South by Southwest (SXSW) music and film festival in Austin, Texas, on March 14, 2011.

Internet Explorer 9 is only supported on Windows Vista SP2, Windows 7, and Windows Server 2008. 

It supports several CSS 3 properties (including border-radius, box-shadow, etc.), embedded ICC v2 or v4 color profiles support via Windows Color System. 

The 32-bit version has faster JavaScript performance, this being due to a new JavaScript engine called "Chakra". 

It also features hardware accelerated graphics rendering using Direct2D, hardware-accelerated text rendering using DirectWrite, hardware-accelerated video rendering using Media Foundation, imaging support provided by Windows Imaging Component, and high fidelity printing powered by the XPS print pipeline. 

IE9 also supports the HTML5 video and audio tags and the Web Open Font Format. 

Internet Explorer 9 initially scored 95/100 on the Acid3 test, but has passed 100/100 since the test was updated in September 2011.