EtherPad : Etherpad is an Open Source online editor providing collaborative editing in really real-time powered by Node.js
Mockingbird : Mockingbird is an online tool that makes it easy for you to create, link together, preview, and share mockups of your website or application.
SumoPaint : Powerful graphics editor for your web browser and pc
SQL Fiddle : A tool for easy online testing and sharing of database problems and their solutions.
Maqetta : Maqetta is an open source project that provides WYSIWYG visual authoring of HTML5 user interfaces. The Maqetta application itself is authored in HTML,...
A better way to conduct remote interviews
WebRTC based video chat + code editor = Awesome interviews
