The document discusses debugging tools in web browsers. It provides an agenda that covers problems that need debugging like JavaScript errors, resource loading, alignment/CSS issues, and supporting multiple platforms. It then discusses the built-in developer tools in browsers like Chrome, Safari, Firefox, Internet Explorer, and Opera and demonstrates some of their features. It also mentions tools for testing cross-browser compatibility like BrowserShots and Spoon. Finally, it lists some useful Firefox add-ons and Chrome extensions.