ActiveHs is a Haskell source code presentation tool, developed for education purposes. User's Guide: <http://pnyf.inf.elte.hu:8000/UsersGuide_en.xml> Developer's Documentation (partial): <http://pnyf.inf.elte.hu:8000/DevDoc_en.xml> The software is in prototype phase, although it already served more than 700 000 user requests at Eötvös Loránd University Budapest, Hungary. Note that this software has many rough edges; you are welcome to work on it!