Ok. I'd be interested in the following benchmark: A program that reads in a large map of key-value pairs; it then reads in a list of keys, and produces a list of values (order of the output is not important). The map can be modeled by e.g. a red/black tree.

I'd be interested in the performance in Haskell, if it was implemented using a number of worker threads (each with their own reference to the map), versus the best implementation you can think of in HVM.