@hackage halfs0.2

Halfs is a filesystem implemented in the functional programming language Haskell. Halfs can be mounted and used like any other Linux filesystem, or used as a library. Halfs is a fork (and a port) of the filesystem developed by Galois Connections. See also http://haskell.org/pipermail/haskell-cafe/2006-April/015361.html

You can get it from here: http://darcs.haskell.org/halfs