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,
Internet Explorer 9 "distinctive and excellent" ActiveX filtering and Tracking Protection features might be "perplexing for less technical users." Having reached release candidate status eleven months after it was originally announced at the March 2010 MIX conference, "Microsoft's development process is too slow." The new version is "a good modern browser" but "the competition is moving faster." "Computing" observed that "the feature set has piled up" since development began, with recent changes including "a completely rejigged JavaScript engine, and far better web standards support." It reported that Internet Explorer 9 RC ranked above Firefox, slightly above Safari, and below Chrome and Opera on