HTML5 is the latest version of HTML that allows for richer content on the web compared to previous versions. It is still being developed but provides features for video, audio, and interactivity that overcome limitations of prior standards. HTML5 works together with CSS and JavaScript to support development of content that can be deployed across devices like smartphones and tablets through browsers. This makes HTML5 well-suited for mobile learning applications since it allows learning content to be accessed directly on mobile devices without additional software.