encoding

Tom Stuart's Ruby Manor 3 talk builds FizzBuzz using nothing but Ruby lambdas, working through Church encodings of numbers, booleans and data structures. It is a hands-on introduction to lambda calculus.

Ned Batchelder's PyCon 2012 talk gives a quick overview of what Unicode is, then focuses on what a Python programmer needs to handle text correctly. It presents the 'Unicode sandwich' strategy: decode bytes at input, work with Unicode internally, encode at output.