This tutorial book presents nine carefully revised lectures given at the 5th International School on Functional Programming, AFP 2004, in Tartu, Estonia in August 2004. The book presents the following nine, carefully cross-reviewed chapters, written by leading authorities in the field: Typing Haskell with an Attribute Grammar, Programming with Arrows, Epigram: Practical Programming with Dependent Types, Combining Datatypes and Effects, GEC: a toolkit for Generic Rapid Prototyping, A Functional Shell that Operates on Typed and Compiled Applications, Declarative Debugging with Buddha, Server-Side Web Programming in WASH, and Refactoring Functional Programs.