The document discusses HTML5 and CSS3, new versions of HTML and CSS that introduce additional features and functionality. It provides an overview of what HTML5 and CSS3 are, who develops their specifications (WHATWG, W3C, IETF), how developers and companies are adopting them, and how to start learning and using the new technologies. The document encourages developers to start building projects with HTML5 and CSS3 now rather than waiting due to benefits like improved user experiences across devices and more flexibility in design.