Mind42 : Collaborative mind mapping in your browser
SQL Fiddle : A tool for easy online testing and sharing of database problems and their solutions.
EtherPad : Etherpad is an Open Source online editor providing collaborative editing in really real-time powered by Node.js
MindMeister : MindMeister is an online mind mapping tool that lets you capture, develop and share ideas visually.
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.
