MaxQ (http://maxq.tigris.org/) is a web testing tool that allows you to record HTTP sessions and play them back. The :bbMaxQ step runs this framework.
from buildbot.plugins import steps
f.addStep(steps.MaxQ(testdir='tests/'))The single argument, testdir, specifies where the tests should be run. This directory will be passed to the run_maxq.py command, and the results analyzed.