minitest version 2.5.1 has been released!
minitest provides a complete suite of testing facilities supporting
TDD, BDD, mocking, and benchmarking.
minitest/unit is a small and incredibly fast unit testing framework.
It provides a rich set of assertions to make your tests clean and
readable.
minitest/spec is a functionally complete spec engine. It hooks onto
minitest/unit and seamlessly bridges test assertions over to spec
expectations.
minitest/benchmark is an awesome way to assert the performance of your
algorithms in a repeatable manner. Now you can assert that your newb
co-worker doesn’t replace your linear algorithm with an exponential
one!
minitest/mock by Steven B., is a beautifully tiny mock object
framework.
minitest/pride shows pride in testing and adds coloring to your test
output. I guess it is an example of how to write IO pipes too. 
minitest/unit is meant to have a clean implementation for language
implementors that need a minimal set of methods to bootstrap a working
test suite. For example, there is no magic involved for test-case
discovery.
Changes:
2.5.1 / 2011-08-27
-
2 minor enhancements:
- Added gem activation for minitest in minitest/autoload to help out
1.9 users - Extended Spec.register_spec_type to allow for procs instead of just
regexps.
- Added gem activation for minitest in minitest/autoload to help out