jWYSIWYG is a jQuery plugin to create WYSIWYG editor. It's customizable and easy to use. It can be used with some other plugins and it has RTL support.
jQuery.localizationTool.js is a simple localization dropdown for your one page website. Translates strings in the languages you provide. It supports RTL(right-to-left) text.
Feedback Me is a jQuery plugin allows user to easily add an animatable UI widget with a feedback form which slides from the side of the screen.
typeahead.js is a fast and fully-featured autocomplete library that is inspired by Twitter's autocomplete search functionality.