The most important criterion for GO Consortium membership is that the members contribute something to the collection of resources that we make available to the public (almost all member contribute annotations; several contribute to the ontologies; a few contribute software). The scientists involved in working with GO in these member groups communicate via the GO mailing list to discuss development issues in the ontologies. If you represent a database that wishes to join the GO Consortium please write to the mailing list to inquire about the criteria for joining. The current consortium member groups must all agree to inclusion of a new member group, and so writing to the mailing list is a good way to reach all the groups and begin the process. Anyone with a more general interest in the GO may join the firstname.lastname@example.org mailing list or subscribe to the Twitter feed (@news4go) to receive updates about the GO.