Chameleon is a Haskell-style language which provides a flexible overloading mechanism based on Constraint Handling Rules (CHRs). The user can impose conditions on overloaded identifiers via CHRs. For example, consider the functional dependency class Collects ce e | ce -> e where ... In Chameleon, we would provide instead the following CHR: rule Collects ce e, Collects ce e' ==> e=e' The latest version including a number of examples can be down-loaded from here: http://www.cs.mu.oz.au/~sulzmann/chameleon Currently, we have only implemented the front-end, i.e. the type checker. Also available are three papers - "Beyond Type Classes", describing the connection and differences compared to Haskell-style type classes. - "A Theory of Overloading", describing the theoretical machinery behind the Chameleon language. - "A Theory of Overloading Part II: Semantics and Coherence", describing an implementation scheme which we yet have to implement. The papers can be found under: http://www.cs.mu.oz.au/~sulzmann/chr Cheers, Martin