The document discusses various testing tools used for Rails applications including Test::Unit, Shoulda, webrat, RSpec, Cucumber. It provides examples of feature definitions, scenarios, and step definitions using Cucumber for acceptance testing and RSpec/Shoulda for controller testing. It recommends Cucumber/webrat for view testing, RSpec/Shoulda for controller testing, and Shoulda/Test::Unit for model testing. It also mentions some other tools like Factory Girl, Mocha, Autotest, and RCov.