Mind42 : Collaborative mind mapping in your browser
repl.it : Powerful and simple online compiler, IDE, interpreter, and REPL. Code, compile, and run code in 30+ programming languages. including JavaScript, Pytho...
Ready for Rails 4? : Check easily whether a gem is ready for Rails 4 or not.
Feed43 : Your favorite site doesn't provide news feeds?
This free online service converts any web page to an RSS feed on the fly.
MindMeister is an online mind mapping tool that lets you capture, develop and share ideas visually.