Internet Explorer 9 Mobile will be available for Windows Phone 7 in the next major update to Windows Phone 7 called “Mango”.
The current version of IE on Windows Phone 7 is IE 7 Mobile which is installed by default. IE 9 Mobile will be HTML 5 enabled with support for multi-tasking for third party apps. While the Mango update of Windows Phone 7 is scheduled on March 8, 2011, IE 9 RC has already been released by Microsoft which can be downloaded and used on your Windows Vista and Windows 7 PCs. You can download Internet Explorer 9 RC (32-bit and 64-bit) offline installers.