Nice slides, "High Wizardry in the Land of Scala Presentation" by Daniel Spiewak, in pages 4-36 he shows Higher-Kinds and Typeclasses, that can be interesting for D programmers too: http://assets.en.oreilly.com/1/event/45/High%20Wizardry%20in%20the%20Land%20of%20Scala%20Presentation.pdf Bye, bearophile