AJAX has become THE way to build user friendly and dynamic websites. With AJAX, you can update the contents of a page without doing a full page reload. Most websites need this behavior. Read this post to learn how to implement AJAX on WordPress sites.
TinyMCE is a rich-text editor that helps convert the HTML textarea element into a WYSIWYG editor. While working with it recently, I noticed that it doesn’t work well with AJAX out of the box. This article explains the problem and provides a solution.