Internet Explorer is a web browser developed by Microsoft since 1995. The newest version, IE9, was published in 2011 and includes improvements to web standards support and performance.
Mozilla Firefox started as a standalone web browser in 2004 and the newest version, Firefox 4.0, focuses on ease of use and speed improvements.
Google Chrome was first released by Google in 2008 using the WebKit engine and the latest version, Chrome 12.0, was published in 2011. It is the fastest browser but also very secure.