Less is a CSS preprocessor, providing a set of extensions and features to traditional Cascading Style Sheets (CSS) for improved maintainability and ease of styling in web development.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Microsoft Ajax Content Delivery Network hosts popular third party JavaScript libraries such as jQuery and enables you to easily add them to your web applications.