NicEdit is a Javascript/AJAX inline content editor to allow easy editing of web site content on the fly in the browser. It integrates into any site in seconds to make any element/div editable or convert standard textareas to rich text editing.

NicEdit was created as an alternative for the complex and large popular WYSIWYG editors like TinyMCE (which I have used in the past) and FCKEditor. It implements many of the standard rich text features like these editors but is easier to integrate without impact on download size. [via]