
Less (which stands for Leaner Style Sheets) is a backwards-compatible language extension for CSS.
Bootstrap is a free (MIT license) front-end development framework for the creation of websites and web apps. Bootstrap is a powerful, feature-packed front-end toolkit.
jQuery is a fast, small, and feature-rich JavaScript library. It makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers.
Tooltip is a floating element that displays information related to an anchor element when it receives keyboard focus or the mouse hovers over it.