Scion is a Haskell library that aims to implement those parts of a
Haskell IDE which are independent of a particular front-end. Scion
is based on the GHC API and Cabal. It provides both a Haskell API and
a server for non-Haskell clients such as Emacs and Vim.
See the homepage http://code.google.com/p/scion-lib and the README
http://github.com/nominolo/scion/blob/master/README.markdown for
more information.