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
ProtoShare a Microsoft Word doc, as an archived HTML site, or to a web URL. ProtoShare is browser-based software, compatible with multiple operating systems. Internet Explorer 10, latest Firefox, latest Safari, and latest Chrome browsers on both Windows and Mac OS are supported in the Review section of the tool, which is where collaborators interact with and comment on prototypes. Mobile prototypes can also be linked to a handheld mobile device's browser for app simulation. The build and edit functionality of ProtoShare, where developers create the prototypes, is supported by the latest Firefox, Safari, and Chrome browsers on Windows and Mac