Dear Corentin, Dear Chaddai, Dear Lorenzo, Thank you for your replies, they explain everything I didn't understand. Only, I cannot find the new equivalent for the old System.system function, which doesn't appear anymore? At least not in http://www.haskell.org/ghc/docs/7.4-latest/html/libraries/base-4.5.1.0/doc-i... Actually, I always use it in a little helper file I apply in all my Haskell projects. For example, if a project has modules M1.hs and M2.hs, this helper file is -- helper.hs import System import M1 import M2 myhaddock = System.system "haddock -h M1.hs M2.hs" so that I can start each session simply with $ ghci Prelude> :l helper.hs and I can generate the docs M1.html and M2.html for my project simply with Main> myhaddock I could probably do all this with some built-in tools. For example there is Distribution.Simple.Haddock.haddock :: PackageDescription -> LocalBuildInfo -> [PPSuffixHandler] -> IO () but all this might be well programmed, but is so poorly documented, that I am not able figure that out. A while ago I did an intensive study on this whole Cabal, and at that stage I became really frustrated with Haskell. I had spent a lot of time in realizing two nice projects, but I was not able to cabalize and publish them. Since then, I am just waiting and hoping for a thorough introduction (beyond the overwhelming Cabal manual) that explains all that to mere mortals. Anyway, thank you very much again. Regards, Tom