I suspect this means it used top-level declarations in the REPL. Happily, with GHC 7.4[1] (released just now), GHCi accepts any sort of declaration, so it should be much less confusing.
Hallelujah! I do not understand why that feature was deprioritized for a decade, making ghci useless for quickly trying out sample code or quick ideas involving types.
[1]: http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/relea...