Dear Haskellers, The following paper may still benefit from your comment. The final version is only due per 10 August 2006. Thanks, Ralf Laemmel -------------------------------------------------------------------------- http://homepages.cwi.nl/~ralf/gpce06/ Title: Software Extension and Integration with Type Classes Authors: Ralf Lämmel and Klaus Ostermann Abstract The abilities to extend a software module and to integrate a software module into an existing software system without changing existing source code are fundamental challenges in software engineering and programming-language design. We show that these challenges can be tackled, at the level of language expressiveness, by using the language concept of type classes, as it is available in the functional programming language Haskell. A detailed comparison with related work shows that type classes provide a powerful framework in which solutions to known software extension and integration problems can be provided. We also pinpoint several limitations of type classes in this context.