Chameleon (the language) is a Haskell style language to experiment with advanced type extensions such as type classes and generalized algebraic data types. The user can program her own type extensions via Constraint Handling Rules (CHRs). Chameleon (the system) is also a compiler framework. Chameleon has been applied in a number of project such as type error reporting, programming language program verification etc. In the XHaskell implementation we heavily rely on the compiler infrastructure provided by Chameleon. Language Features * LanguageOverview * HowtoinstallandrunChameleon The Compiler * CompilerOverview * ChameleonGecko * StandaloneSolver Applications *TypeErrorDiagnosis *ProgramVerification MartinSulzman