* labs.wikimedia are the old old old labs/test projects, These are no longer (and any that still wanted -> wmflabs) * prototype.wikimedia are oldish test setups, and most should be moved to wmflabs if still wanted *.wmflabs.org are instances hosted on our Labs setup[1] which is our virtuazlization cluster/project that Ryan setup, Which houses more than just test wikis (Think Toolserver, but yes, with test wikis as well).