They are the creators of Thrift which they created for internal use and then published/open-sourced.. It is a multi-language RPC API/Service. When it went public, one of the languages interfaces they provided was Haskell. So yes. They use Haskell somewhere inside Facebook.
Interesting:So they use Haskell at Facebook?
Dave
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe