This document discusses HTML5, CSS3, and their use and implementation in WordPress themes and plugins. It provides a brief history of web standards and outlines some HTML5 features that WordPress developers can currently utilize, such as responsive design with CSS media queries, font-face, transitions, and local storage. While browser support for HTML5 is solid for many elements, transformations and embedded media can still be dicey. Resources for learning more about HTML5 and WordPress are provided.