Lambda the Ultimate

OOHaskell by Oleg Kiselyov, Ralf Lämmel, and Keean Schupke

from the abstract:
"This paper makes the next logical step and shows that Haskell readily supports objects encapsulating methods and mutable fields, lexically scoped classes with initializers, overriding, inheritance, abstract classes, first-class interfaces, virtual and private methods, multiple and diamond inheritance, class and method polymorphism."