Firefox to US$7,500 cash reward) to researchers who discover severe security holes in Firefox. Official guidelines for handling security vulnerabilities discourage early disclosure of vulnerabilities so as not to give potential attackers an advantage in creating exploits. Because Firefox generally has fewer publicly known security vulnerabilities than Internet Explorer (see "Comparison of web browsers"), improved security is often cited as a reason to switch from Internet Explorer to Firefox. "The Washington Post" reported that exploit code for known critical security vulnerabilities in Internet Explorer was available for 284 days in 2006. In comparison, exploit code for known, critical security vulnerabilities in
Browser wars of Chrome on weekdays up until July 4. At the same time, Net Applications reported Internet Explorer firmly in first place, with Google Chrome almost overtaking Firefox as the second. In 2012, responding to Chrome's popularity, Apple discontinued Safari for Windows. Microsoft released Internet Explorer 9 on March 14, 2011. It featured a revamped interface, support for the basic SVG feature set, and partial HTML5 video support, among other new features. It only runs on Windows Vista, Windows 7, and Windows Phone 7. The company later released Internet Explorer 10 along with Windows 8 and Windows Phone 8 in 2012,