A simple step-by-step debugger for the WHILE-language as described in the book "Computability and Complexity from a Programming Perspective" by Neil Jones
A grammar for Haskell, close to the specification in the Haskell report is given. This is especially interesting, as many rules given in the report are hard to implement.
M. Grahl, A. Hotho, and G. Stumme. Workshop Proceedings of Lernen - Wissensentdeckung - Adaptivität (LWA 2007), page 50-54. Martin-Luther-Universität Halle-Wittenberg, (September 2007)