Internet Explorer 10 for the next version, Michael Muchmore of "PC Magazine" tested Platform Preview 1's performance and HTML5 support with both Microsoft's and third parties' test suites. In his test, Platform Preview 1 performed better than Internet Explorer 9 but not always better than the competing web browsers. On September 13, 2011, Microsoft released the developer preview of Windows 8 to general public, which came with Internet Explorer Developer Preview (the first full browser incarnation of Internet Explorer 10). Although Internet Explorer is the last major web browser – among Mozilla Firefox, Google Chrome, Opera, and Safari – to support spell checking,
WebSocket in Firefox 6, Safari 6, Google Chrome 14, Opera 12.10 and Internet Explorer 10. A detailed protocol test suite report lists the conformance of those browsers to specific protocol aspects. An older, less secure version of the protocol was implemented in Opera 11 and Safari 5, as well as the mobile version of Safari in iOS 4.2. The BlackBerry Browser in OS7 implements WebSockets. Because of vulnerabilities, it was disabled in Firefox 4 and 5, and Opera 11. To establish a WebSocket connection, the client sends a WebSocket handshake request, for which the server returns a WebSocket handshake response, as