Developers are some of the last people still clinging to their desktops and laptops because they want the faster connection and control that desktops and laptops provide. But that is slowly changing as development is moving into the cloud. Soon big, integrated development environments will be living in the cloud where they can build faster and store more code. One of the crucial parts of the equation is CodeMirror, a browser-based code editor with highlighting and customization for dozens of the most popular langauges. You won't need to work with a basic TextArea block any longer. Available with the MIT license.