A cloud-development platform for developers, where with every free sign-up, you get a virtual-machine, complete with root access, 2GB RAM and 1.2GB storage. You can view, manage and create files right in the browser. It even has a terminal emulator which too runs in the browser.
The VM is sort of pre-configured with NodeJS, PHP, Apache, MySQL e.t.c. and you can always install whatever packages you need. You can import personal projects from your disk, into the cloud, and you can also create new ones, using a few presets for a start. The _presets _here refers to _Bootstrap, AngularJS, WordPress _e.t.c. So the idea is that it would just create all the necessary files, and prevent you with like a template that you are free to edit to suit your needs.
The development-UI is fine too. You can edit code right in the browser, and view it in a browser app running inside the browser, rather like on W3schools.