Bootstrap Markdown is a plugin for markdown editing. It exposes useful API that allow you to fully hook-in into the plugin.
wysiwyg.js is a lightweight content editable jQuery editor which works with legacy browsers.
A lightweight jQuery WYSIWYG text editor based on HTML5 technology. Cross browser, with mobile support, high performance and Retina Ready flat design.
It's free to use for personal and non-profit projects.
Azexo Composer uses client JS for render of HTML to work faster and save server resources.
Tag Editor is a powerful and lightweight tag editor plugin for jQuery.
Smalleditor is a small WYSIWYG editor with delta save, inspired by Medium.
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.
Editor and generated code are optimized for HTML5 support. Compatible with all recents browsers like IE8+, Chrome, Opera and Firefox. It's only 15kB which means faster page loading.
Treed wants to be for tree editing what ace is for text editing. Extensible, customizible, powerful, and just plain easy to use.
jQuery Notebook is a simple, clean and elegant WYSIWYG rich text editor for web aplications.
jQuery Fullscreen Editor is a lightweight jQuery plugin that adds fullscreen mode to text fields. It transforms textfields to customizable editors, either it can be used within a form or standalone.
This plugin has a very nice visual editor for customizing the JSON data and a visualizer that provides a different view for it.