Atom is text / source code editor based on web technologies and you can tweak its interface with CSS or easily add new features with HTML and Javascript, at least according to its website.
The text editor features Node.js integration, allowing you to seamlessly mix usage of Node and browser APIs. And of course, since it’s developed by GitHub, it features built-in Git integration. Until now, to use Atom in Ubuntu you’d have to compile it but I like to make things easier for you so I’ve built it on my computer (Nodejs apps can’t be built directly in Launchpad PPAs) and uploaded it to a PPA, for Ubuntu 14.04, 13.10 and 12.04 (and derivatives: Linux Mint, elementary OS, etc.).