In response to the discussion What makes Haskell difficult as .NET? http://groups.google.ca/group/haskell-cafe/browse_thread/thread/f61ee38f2082... I thought I'd start a discussion on what object oriented features Haskell supports. A good reference is: Haskell's Overlooked Object System http://homepages.cwi.nl/~ralf/OOHaskell/paper.pdf The comparison is often made of Haskell's classes to interface. However, once we define an instance we have something concrete which is closer to a class under the object oriented paradigm. If our instances are paramatric: MyType a = MyType{.......child::a} Then when we can create subclass instances which are sybtypes of our Paramatric type. This gives us inheritance. Overriding might be slightly trickier. We can certainly create new instances of the parent class for a specific subtype. As a minimum we will need to specify each method we created which is not defined in terms of the others (our getters and setters) and perhaps we are allowed to over ride the methods which are derived from the other methods. Anyway, I'll do some re reading of the paper, experiment with some code and see what other options there are.