[benbataille]

I tend to disagree with you in the sens that Damas-Milner seems to me as the typical exemple of an algorithm which seems simple but actually have subtle implication and trade-off. Robinson's unification which is at the center of the algorithm is already made a bit tricky by quantification as soon as you have polymorphism. Then, some rules have actually deeper implication and trade-off than it seems (especially let).

For people interested in type checkers, there is a couple of really good chapters by written by Peter Hancock in a book available online : The Implementation of Functional Programming Languages by Simon Peyton Jones. They entirely cover the theory and there is a complete implementation in Miranda. Here is the link : http://research.microsoft.com/en-us/um/people/simonpj/papers...