This book is a guide on how one can program in Haskell. Haskell is a pure functional programming language. The book begins by giving you a brief overview of the Haskell programming language so that you may know what it is. You are then guided on how to get started with Haskell programming. This involves setting up the Glasgow Haskell compiler which forms the heart of programming in Haskell. You are also guided on how to compile your Haskell scripts. Haskell marks the first programming language to introduce typeclasses into programming. This book explores this in detail. In Haskell, expressions are a common feature when writing scripts. This book guides you on how to use Haskell compiler so as to determine the kind of expression that you have written. Type variables are explored in detail. There are several typeclasses in Haskell. Most of these have been discussed in this book, and you are shown how to use each of those classes. Higher order functions are also examined. In Haskell, functions should only take one parameter. However, it is possible for one to override this mechanism and create a function with more than one parameter. This is usually done using curried functions. This book guides you on how to implement such functions in your code. This book guides you on how to implement the Lambda functions in Haskell. Input and output forms a significant part in any programming language. You are guided on how to obtain user data in Haskell and then provide them with output based on that input. The following topics are discussed in this book: - What is Haskell? - Getting Started - Types and Types and Typeclasses in Haskell - Higher Order Functions - Modules - Input and Output - Zippers