GHC Install Without Root

I did this too. I created a directory ~/usr and passed --prefix=$HOME/usr to all configure scripts. Using the Haskell Platform makes this process even smoother.

You obviously need a directory that all pertinent users have at least read permission on. Say /home/foo, with subdirectories bin, lib, share, .cabal. Then ./configure --prefix=/home/foo and make && make install, and make sure that /home/foo/* is before /usr/* in everybody's PATH, LIBRARY_PATH etc. You should probably start with installing gcc and c-libs there, and when everything C is installed, install ghc.