Code Editor

Ace Editor (Javascript Mode)

You can find the offical website
/**
 * In fact, you're looking at ACE right now. Go ahead and play with it!
 *
 * We are currently showing off the JavaScript mode. ACE has support for 45
 * language modes and 24 color themes!
 */
function add(x, y) {
    var resultString = "Hello, ACE! The result of your math is: ";
    var result = x + y;
    return resultString + result;
}
var addResult = add(3, 2);
console.log(addResult);
            

Ace Editor (Html Mode And Emmet)

You can find the offical website
<!--
* We are currently showing off the Html mode. ACE has support for 45
* language modes and 24 color themes!
 -->
<!DOCTYPE html>
<html lang="en">
<head>
<title>ACE in Action</title>
<style>
    #editor {
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
    }
</style>
</head>
<body>
<div id="editor">function foo(items) {
    var x = "All this is syntax highlighted";
    return x;
}</div>
<script src="/ace-builds/src-noconflict/ace.js" charset="utf-8"></script>
<script>
    var editor = ace.edit("editor");
    editor.setTheme("ace/theme/monokai");
    editor.getSession().setMode("ace/mode/javascript");
</script>
</body>
</html>
            

Ace Editor (Css Editor)

You can find the offical website

        /* Some example CSS */

        @import url("something.css");

        body {
        margin: 0;
        padding: 3em 6em;
        font-family: tahoma, arial, sans-serif;
        color: #000;
        }

        #navigation a {
        font-weight: bold;
        text-decoration: none !important;
        }

        h1 {
        font-size: 2.5em;
        }

        h2 {
        font-size: 1.7em;
        }

        h1:before, h2:before {
        content: "::";
        }

        code {
        font-family: courier, monospace;
        font-size: 80%;
        color: #418A8A;
        }