PHP syntax highlighting code editor

I need a configureable and extendable in browser code editor using JS and/or PHP (no python or flash etc).

Something like code.google.com editor (it rocks!) and I really like the diff capability it provides. It would be cool but I can't find info on what editor it is employing.

Anyone know something like that? Or if c开发者_StackOverflow社区ode.google.com's code is open Source? If yes, where can I get it?

I think this has been previously answered with CodeMirror being the preferred choice and it is apparently used by Googles code playground. See Is there a good in-browser code editor? for more information.