* [Penn lambda calculator](http://www.ling.upenn.edu/lambda/) Pedagogical software developed by Lucas Champollion, Josh Tauberer and Maribel Romero.<p>
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* [[!wikipedia Moses Schönfinkel]]
* [[!wikipedia Haskell Curry]]
* [[!wikipedia Alonzo Church]]<p>
<http://people.cs.uu.nl/jeroen/article/combinat/combinat.ps>
* [Chris Barker's Iota and Jot](http://semarch.linguistics.fas.nyu.edu/barker/Iota/)<p>
+* [To Dissect a Mockingbird](http://dkeenan.com/Lambda/index.htm)
+* [Combinator Birds](http://www.angelfire.com/tx4/cus/combinator/birds.html)
+* [Les deux combinateurs et la totalite](http://www.paulbraffort.net/j_et_i/j_et_i.html) by Paul Braffort.
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## Evaluation Order ##
* [[!wikipedia Evaluation strategy]]
* [The Y Combinator](http://dangermouse.brynmawr.edu/cs245/ycomb_jim.html) derives the applicative-order Y-combinator from scratch, in Scheme. This derivation is similar in flavor to the derivation found in The Little Schemer, but uses a slightly different starting approach...
* [The church of the least fixed point, by Sans Pareil](http://www.springerlink.com/content/n4t2v573m58g2755/)
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## Types ##
* [[!wikipedia Tagged union]]