[titzer]

They look a lot nicer in ML and Haskell, IMO.

Of course I implemented them in Virgil, too. (shameless plug: https://github.com/titzer/virgil)

[harrisi]

I don't intend to derail the discussion further, but I'm curious about Virgil. I can't find any information on it that tells me who is behind it or how to contact them. Do you have anywhere I could look to learn more about the project in general?

[titzer]

Sure! It's pretty much just my perennial side project since at least 2004. Some information is available in publications (latest: http://dl.acm.org/citation.cfm?id=2491962), and there is some documentation in the wiki branch (https://github.com/titzer/virgil/tree/wiki).