Nemerle
Nemerle is a high-level statically-typed programming language for the .NET (see also Mono) platform. It offers functional, object-oriented and imperative features. It has a simple C#-like syntax and a powerful meta-programming system.
Features that come from the functional land are variants (aka algebraic data types), pattern matching, type inference and parameter polymorphism (aka generics). The meta-programming system allows great compiler extensibility, embedding domain specific languages, partial evaluation and aspect-oriented programming.
It was developped at the Wroclaw University by Kamil Skalski, Michał Moskal, Prof. Leszek Pacholski and Paweł Olszta. It has been named after the mage Nemmerle from "A Wizard of Earthsea" by Ursula K. Le Guin (spelling with a single m is a design decision).