MiniTest is a full-featured testing framework for Ruby that ships with the standard library in Ruby 1.9. Unlike some of the more well-known incumbents in the Ruby testing world, the MiniTest library is blazing fast and incredibly concise. It can be used for writing unit tests, BDD-style expectations, mocks, and benchmarks. Become familiar with MiniTest, and you'll gain a valuable tool you can use to improve any Ruby project you'll ever work on.