markItUp! is a JavaScript plugin built on the jQuery library. It allows you to turn any textarea into a markup editor. Html, Textile, Wiki Syntax, Markdown, BBcode or even your own Markup system can be easily implemented.
markItUp! is not meant to be a “Full-Features-Out-of-the-Box”-editor. Instead it is a very lightweight, customizable and flexible engine made to meet the developer's needs in their CMSes, blogs, forums or websites. markItUp! is not a WYSIWYG editor, and it never will be.
Home: http://markitup.jaysalvat.com/
Documentation: http://markitup.jaysalvat.com/documentation/
Examples: http://markitup.jaysalvat.com/examples/