Linq went live in C# in November, as part of .Net 3.5. It adds lots of FP-things to C#. It's really fun to be able to use Haskell-ish things in C#. Manipulating lists and collections just got *much* easier. Things it does: - map, fold, filter are all there (they're called "select", "agregate", "where") - limited support for laziness (since .Net 2.0; you can write a lazy "zip" function; I couldnt figure out how to write a lazy "unzip" function) - you can extend the methods available on all lists and collections - lambda expressions - type inferrence (technically, this is part of .Net 3.x, rather than specific to Linq). Things it doesnt do: - recursion doesnt seem particularly optimized (quick 2 minute test, I could be wrong) - no way to enforce purity It's an interesting vindication of the ideas in Haskell that C#, a big mainstream language, has integrated ideas from it, and that they're in production today.