Microsoft's IE9 is available and ready for download.

The new version, officially released at midnight, promises lightning-fast speed and significant graphics improvements. According to Mashable.com, IE9's beta version has already been downloaded more than 40,000 times, and isn't simply an updated version of IE8, but is a dynamic rebuilt browser altogether. IE9 also includes new security features, a redesigned UI and supports HTML5.

Take a tour of IE9's new interface.

What are your thoughts on IE9?