Gabriel439/Haskell-Pipes-Library — pull request #13 by DanBurton (2012-07-23 00:25:07+00:00)
Title: instance MonadIO (FreeT f m)

I was just writing up [an answer on StackOverflow](http://stackoverflow.com/a/11604953/208257) using Control.Pipe, and realized that Pipe is not an instance of MonadIO. Given the dependency on transformers is already there, I see no reason to omit it. You may want to consider adding an IMonadIO class to index-core as well.