JS(Javascript)はクライアントデバイスの操作システムを検出します.

          ，           macosx   ，       ，   font-size，         ，    macosx   。           js navigator.platform          ，    macosx    class,            ，             。

function detectOS() {
    var sUserAgent = navigator.userAgent;
    var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");
    var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC") || (navigator.platform == "Macintosh") || (navigator.platform == "MacIntel");
    if (isMac) return "Mac";
    var isUnix = (navigator.platform == "X11") && !isWin && !isMac;
    if (isUnix) return "Unix";
    var isLinux = (String(navigator.platform).indexOf("Linux") > -1);
    if (isLinux) return "Linux";
    if (isWin) {
        var isWin2K = sUserAgent.indexOf("Windows NT 5.0") > -1 || sUserAgent.indexOf("Windows 2000") > -1;
        if (isWin2K) return "Win2000";
        var isWinXP = sUserAgent.indexOf("Windows NT 5.1") > -1 || sUserAgent.indexOf("Windows XP") > -1;
        if (isWinXP) return "WinXP";
        var isWin2003 = sUserAgent.indexOf("Windows NT 5.2") > -1 || sUserAgent.indexOf("Windows 2003") > -1;
        if (isWin2003) return "Win2003";
        var isWinVista= sUserAgent.indexOf("Windows NT 6.0") > -1 || sUserAgent.indexOf("Windows Vista") > -1;
        if (isWinVista) return "WinVista";
        var isWin7 = sUserAgent.indexOf("Windows NT 6.1") > -1 || sUserAgent.indexOf("Windows 7") > -1;
        if (isWin7) return "Win7";
    }
    return "other";
}
 
document.writeln("       ：" + detectOS());