[Haskell-cafe] online Real World Haskell - tool used?

[Sophie]

Not a Haskell question, pardon me.

I believe the online Real World Haskell book with commenting system was 
generated with an open-source tool (written by one of the authors?). 
Any idea where I might find this?

[I think I had gotten the link long ago, lost it].

I am also curious what authoring tools were used to write the book.

Thanks!

Sophie