Koding vs Codepen

All languages, databases, and command-line tools are supported. Most machines are already set up with web project basics like Apache, PHP, MySQL, Ruby, Node.js, Perl, and Python and anything else can be installed via the SSH root access.

And link account to oDesk and Facebook.

Koding has a community feature that makes it easy to collaborate and share ideas with like minded developers all over the world. And the community itself is very active and helpful community.

Real-time code and terminal collaboration with integrated chat abilities.

With 256-color support.

Koding supports drag & drop, Dropbox, clone from Github, FTP and the ability to access them using SSH.

The Koding Package Manager (a successor to Apps) is command line tool for installing packages like nginx, Redis, VNC, Wordpress and many others. It consists of officially supported and user-built packages.

Ability to create different sized communities that can be public or private.

There's a built-in social network with developers from all over the world.

Unlimited user-defined domains and subdomains for private or shared VMs can be set up.

Koding uses the Ace editor that's developed by Cloud9. Besides the basics, it covers most important advanced code editor features such as code folding, converting cases, auto-completion, code analysis and refactoring, regex search and offers easy access to relevant documentation.

It also gives access to the CLI, has support for Vim and Emacs keybindings, includes multiple cursors and zen coding mode that removes all distractions and allows focusing on code.

CodePen makes it really easy to export code as a zip or Github Gist.

CodePen has an impressive amount of support for preprocessors (such as Jade, Haml, Slim, Sass, Less, Stylus, Coffeescript and PostCSS). There is also plenty of frameworks and libraries to pick from (Foundation, Bootstrap, Angular, D3, Backbone, Ember etc.).

The codepen profile page allows you to display all of your public pens, and control which order you want them to be viewed in. This is great for showing off your work to possible employers, other devs etc..

To fork a pen only requires clicking one button, and you'll be able to modify the pen on your own account.

You can search through other pens, either by keyword or popular, picked or recent.