Explore the impact of HTML5 and the open web in this presentation from MDN Hack Day in Sao Paulo, Brazil. Delve into topics such as browser fingerprinting, semantic markup, and the advantages of building for cross-platform compatibility. Learn about new HTML elements, video integration, and advanced features like WebSockets and the History API. Discover offline capabilities, WebGL applications, and mobile browser support. Gain insights into the readiness and worth of HTML5 adoption, illustrated with examples from major tech companies and cultural institutions. Understand how these technologies are shaping the future of web development and user experiences.