A new feature slipped into 5.00.1, but it looks like the documentation to go with it didn't get merged (probably my fault, sorry about that). You can now load packages from the GHCi prompt, like so: ___ ___ _ / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 5.00.1, For Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package std ... linking ... :done. Prelude> :set -package lang Loading package lang ... linking ... done. Prelude> :set -package util Loading package concurrent ... linking ... done. Loading package posix ... linking ... done. Loading package util ... linking ... done. Prelude> This means you can also load packages from .ghci files too. Cheers, Simon