One of the things I’ve been working on the last few years, when they pry me away from my C++, is the Haxl project at facebook. Here’s some links…
There is no Fork: an Abstraction for Efficient, Concurrent, and Concise Data Access
Here is a talk I gave on this topic. This talk is very light on the Haskell/language details and heavier on the motivation and how it fits into practice at Facebook.
If you want a more detailed talk on the language bits, here’s Simon Marlow’s talk at ICFP: