#collaborative ide

Some of you might already know about Cloud9 and/or their IDE, what you might not also know is it's available as the successor to Skywriter, Bespin--

Along with being integrated on GitHub you can use Ace Editor nearly anywhere, here's the skinny on it's current features:

Syntax highlighting   

Auto indentation and outdent

An optional command line

Work with huge documents (100,000 lines and more are no problem)

Fully customizable key bindings including VI and Emacs modes

Themes (TextMate themes can be imported)

Search and replace with regular expressions

Highlight matching parentheses

Toggle between soft tabs and real tabs

Displays hidden characters