CodeHighlight is a quite young but very intesting extension. It’s idea is to provide an ability to turn any text field on a web page into powerful source code editor with a such sweet features like syntax highlighting syntax errors checking. If you ever tried to edit some peace of HTML or CSS code in your browser, then you should immediately get an idea. Yes, today we have a lot of powerful source code editors for any possible programming languages. But it is not very convenient to use them for a such small tasks. So, this extension can be a great tool which will save you tons of time and make your life a bit more easy. Feel free to check it and share your feedback with the developers.