Ok,

Thanks all ones for answers...

I imagine that designing applications with functional languages is much
different than with imperative ones.
I was wondering on which points the difference is significant?
Does common oriented object design patterns can be used with OCaml?
And what, for a developer, is the work to do to change his way of
thinking?

I envisage to learn OCaml deeply and than I want to set the basis to do
the change from imperative languages to functional ones.

P.S. : somebody have reference books which goes over this subject?
-- 
Julien Peeters
Computer science student in second year of Bachelor
Science Faculty of Orsay
University of Paris-Sud XI (France)
Personal website: http://www.oxylin.fr