Book excerpt: If you're ready to use Closure to build rich web applications with JavaScript, this hands-on guide has precisely what you need to learn this suite of tools in depth. Closure makes it easy for experienced JavaScript developers to write and maintain large and complex codebases—as Google has demonstrated by using Closure with Gmail, Google Docs, and Google Maps. Author and Closure contributor Michael Bolin has included numerous code examples and best practices, as well as valuable information not available publicly until now. You'll learn all about Closure's Library, Compiler, Templates, testing framework, and Inspector—including how to minify JavaScript code with the Compiler, and why the combination of the Compiler and the Library is what sets Closure apart from other JavaScript toolkits. Learn how the Compiler significantly reduces the amount of JavaScript users have to download when visiting your site Discover several ways to use the Compiler as part of your build process Learn about type expressions, primitives, and common utilities Understand how Closure emulates classes and class-based inheritance Use Closure Templates on the server and the client from either JavaScript or Java Test and debug your JavaScript code, even when it's compiled