Hi again, Well, it seems like my little question raised an interesting thread, and brought me some valuable information. I am pleased to see that the Haskell community is particularily aware of the fact that being a fast language is far from being the most important criterium in most languages choice. Still, the application I am working on has major performance constraints, which if unmet may result in the project to be stopped. I also have to convince both clients and managers of the adequation of my choice regarding these constraints, and I must say that I would already have trouble to introduce something different than C or C++ (they are rather oldschool corporate people ;). For now, I assume that Haskell is very expressive, but has the speed of most interpreted language, which makes it an average choice for my application. However, I think that Haskell laziness could be of great value : I will have most of the application data stored in a database, so I could gain a lot of time in only loading what is useful for a processing. So I guess that everything lies in how I easily (and efficiently) I can mix C++ and Haskell. Thanks to all who answered :) -- Sébastien