This fast-moving guide introduces web application development with Haskell and Yesod, a potent language/framework combination that supports high-performing applications that are modular, type-safe, and concise. You'll work with several samples to explore the way Yesod handles widgets, forms, persistence, and RESTful content. You also get an introduction to various Haskell tools to supplement your basic knowledge of the language.By the time you finish this book, you'll create a production-quality web application with Yesod's ready-to-use scaffolding. You'll also examine several real-world examples, including a blog, a wiki, a JSON web service, and a Sphinx search server.Build a simple application to learn Yesod's foundation datatype and Web Application Interface (WAI) Use Shakespearean template languages for HTML, CSS, and Javascript output Produce cleaner, more modular code by learning how Yesod monads interact Implement the yesod-form declarative API to build forms on top of widgets Learn how Yesod and Haskell store session data and handle persistence Use techniques to serve an HTML page and a machine-friendly JSON page from the same URL Create reusable components for several applications with Yesod subsites