FYI, other operating systems in Haskell:
House, 2005: https://programatica.cs.pdx.edu//House/
HalVM, 2008: https://github.com/GaloisInc/HaLVM
also
HalNS network stack 2011: https://mail.haskell.org/pipermail/haskell-cafe/2011-May/092...