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.
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
F. Mitzlaff, M. Atzmueller, D. Benz, A. Hotho, and G. Stumme. Analysis of Social Media and Ubiquitous Data, volume 6904 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2011)
S. Feng, L. Zhang, B. Li, D. Wang, G. Yu, and K. Wong. Proceedings of the 2013 Conference on Empirical Methods in Natural Language Processing, Seattle, Washington, USA, Association for Computational Linguistics, (October 2013)