This directory should at some point contain lots of fancy unit (and not-so-unit) tests. There are two kinds of unittests in here: *test.py -- tests for python's plain unittest framework test_*.py -- tests for twisted's trail framework (i.e., tests needing a reactor). One could probably use trial for the unittest tests as well. In addition, runAllTests guesses what modules might contain unittests and adds them to its test suite as well.