Online reading for anonymous functions, unit testing, and distributed version control system (DVCS)


WikiBook Ruby unit testing: a simple number test example, list of avaible assertations, setup/teardown


Relish page on rspec-core: get-started example at the end (test driven development), shared examples and contexts

Anonymous functions

Ruby Procs and Lambdas and the difference by Alan Skorkin: good descriptions and examples, plus a picture of "first class"

Distributed version control

Illustrated intro by Kalid Azad: diagrams, key concepts and properties, Mercurial (hg) commands