In XMPP, a group chat is called a "Multi-User Chat", MUC for short. To connect to the MUC's you can view the channels by letting your XMPP client query conference.openvoipalliance.org, which will return a list of channels you can join.
This is how you can browse and connect to channels using the Converse client hosted at xmpp.openvoipalliance.org:
