Lambda the Ultimate

Ralf Hinze and Andres Löh. Generic Programming, Now!. In Roland Backhouse, Jeremy Gibbons, Ralf Hinze and Johan Jeuring, editors, Spring School on Generic Programming, Lecture Notes in Computer Science. Springer-Verlag, 2006.

Tired of writing boilerplate code? Tired of repeating essentially the same function definition for lots of different data types? Datatype-generic programming promises to end these coding nightmares. In these lecture notes, we present the key abstractions of datatype-generic programming, give several applications, and provide an elegant embedding of generic programming into Haskell. The embedding builds on recent advances in type theory: generalised algebraic data types and open data types. We hope to convince you that generic programming is useful and that you can use generic programming techniques today!

Yes, more functional generic programming...

Open data types and open functions are discussed here, but I think this paper wasn't featured on the homepage before.