Bootstrap is a free and open-source CSS framework for mobile-first and responsive front-end web development.
jQuery is one of the most popular, lightweight, “write less, do more”, JavaScript libraries.
Marc has been working with HTML all his career. His knowledge stems from legacy code right the way through to HTML5.
Marc has used CSS all his career, and has knowledge in CSS | CSS2 and CSS3.
PHP ( Hypertext Preprocessor ) is general purpose, open source and widely used scripting language that is suited to Web Development.