Hi all, Thanks for all your answers :) I am still unsure of whether Haskell would be a good competitor against other languages in my case, but it seems like if it does the best option would be to reuse C++ graph libraries and carefully write a wrapper around them to minimize passing values between C and Haskell worlds. In fact, I would like to know how Haskell compares in performance to other languages because if I refer to the page I mentioned (http://www.bagley.org/~doug/shootout/craps.shtml) it does not even compete with Python (which is rather... slow). This is kind of scary, and a quick search on the net turned out to confirm this : The test shows the performance ratio CC++ / Haskell (ghc-4.04) between 10 and 15 from http://www.dcs.gla.ac.uk/mail-www/haskell/msg02153.html. It would be nice if I could get some papers or benchmarks on how Haskell performs and scales. Cheers, -- Sébastien. PS: Regarding Java, it may be surprising, but when it comes to computation (non-GUI stuff) it behaves surprisingly fast, and when used properly can really compete with C++.