* [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)
-* [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).
+* The UPenn [Lambda Calculator](http://dylanbumford.com/LambdaCalculator/): Pedagogical software developed by Lucas Champollion and others. Linguistically oriented, uses types. Requires Java (many users will probably already have Java 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.
* [Matt Might's Lambda Evaluator](http://matt.might.net/articles/implementing-a-programming-language/) in Scheme (R5RS and Racket).