Medium.js
A tiny JavaScript library for making content editable beautiful
...Medium.js also supports placeholders, automatic HR (or BR, or P) creation, events, hotkeys, simple & complex element injection, and more! Medium.js is html5 compliant and has been tested in Firefox, Chrome, Safari, Opera, & IE8+. Browser support is constantly improving! This script is inspired by Medium's beautiful content editor, something we have aspired to emulate since its inception. Much more expressive and customizable than input or textarea. Simply include the dependencies, Medium.js library, CSS, and you are ready to rock. The code within Medium.js editors are very semantic and organized, giving you peace of mind with using content editable.