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
Chakra (JScript engine) Chrome (with V8), and Opera (with Carakan). On March 8, 2011, Microsoft published results showing the 32-bit Internet Explorer 9 to be faster than Safari, Firefox (with TraceMonkey), Chrome, and Opera. March 2011 performance tests for ZDNet concluded that Internet Explorer 9 (32-bit), Chrome 10, and Firefox 4 release candidate were "pretty evenly matched." In 2012, subsequent versions of Chakra, such as the version included in Internet Explorer 10, introduced additional performance changes, including JIT compilation on x64 and ARM architectures, and optimizations related to floating point math and garbage collection. At the Last Call JSCONF in 2015, Microsoft announced