* [Peter Sestoft's Lambda calculus reducer](http://www.itu.dk/people/sestoft/lamreduce/index.html) Very nice! Allows you to select different evaluation strategies, and shows stepwise reductions.
* [Chris Barker's Lambda Tutorial](http://homepages.nyu.edu/~cb125/Lambda)
-* [Mike Thyer's Lambda Animator](http://thyer.name/lambda-animator/) Graphical tool for experimenting with different reduction strategies.
* [Penn Lambda Calculator](http://www.ling.upenn.edu/lambda/) Pedagogical software developed by Lucas Champollion, Josh Tauberer and Maribel Romero. Linguistically oriented. Requires installing Java (Mac users will probably already have it installed).
+* [Mike Thyer's Lambda Animator](http://thyer.name/lambda-animator/) Graphical tool for experimenting with different reduction strategies. Also requires installing Java, and Graphviz.