Micro Code Editor With syntax highlight*

// Switch the language and put some code on me :)           ↑↑↑↑↑↑
// This is a 'Hello World' example.

function greetings(name){
    name = name || "stranger";
    return "Hello, " + name + "!";
}

window.onLoad = alert(greetings());

*thanks to Lea Verou for Prism.js