codeTabber by freginold

codeTabber is a Firefox extension that brings panel-switching keyboard shortcuts to multiple online code editors. codeTabber allows you to switch focus between the various code panels using just the keyboard. The angle brackets, < and >, are used as facsimile arrow keys.

Usage:
To move focus to the next pane, press CTRL and the greater-than key (>). To switch focus to the previous pane, press CTRL and the less-than key (<). If no pane has focus when a keyboard shortcut is used, focus will be given to the first pane. (Mac users: use CTRL rather than CMD.)

Supported sites:
- CodePen
- CSSDeck
- CSSDesk
- dabblet
- JSBin*
- JSFiddle
- kodtest
- Liveweave
- Rendera**
- Stack Overflow (code editor)

* For JSBin: Only the HTML tab shows up initially; load the CSS and JavaScript tabs in order to be able to switch between them.

** For Rendera: In Firefox, the site loads differently depening on if you use HTTP or HTTPS. codeTabber currently only supports Rendera in Firefox over HTTPS.