Is there a client-side IDE for textareas on webpages?

Much of my work involves a web-based CMS I cannot modify. That means lots of textareas, and none of the IDE features I love, such as tab functionality, syntax highlighting, etc.

Are there any browser modifications, or bookmarklets, or anything that would allow a client side inline override of textare开发者_运维技巧as, allowing IDE like features (even as basic as simply allowing use of the tab key instead of alt+009) in a webpage's textarea field?

Yes there are. For example: Web Wiz Rich Text Editor, the first one I found when Googling "browser text editor". :) It appears to be free to use, with paid premium versions.

I'm sure there are others!