Free WYSIWYG HTML5 Rich Text Editor: WYSIHTML5

WYSIHTML5 is an open source rich text editor based on HTML5 technology and the progressive-enhancement approach. It uses a sophisticated security concept and aims to generate fully valid HTML5 markup by preventing unmaintainable tag soups and inline styles.

Major Features

• It’s fast and lightweight (smaller than TinyMCE, Aloha, …)
• Auto-linking of urls as-you-type
• Generates valid and semantic HTML5 markup (even when the content is pasted from MS Word)
• Uses class names instead of inline styles
• Uses sandboxed iframes in order to prevent identity theft through XSS
• Speech-input for Chrome
• It’s library agnostic, no library required (jQuery, Prototype, etc…)