Each module can be configured to use custom implementation by including it in the init.properties, the defaults are as follows:
muc/modules/jabber:iq:version[S]=tigase.component.modules.impl.JabberVersionModule muc/modules/owner[S]=tigase.muc.modules.RoomConfigurationModule muc/modules/presences[S]=tigase.muc.modules.PresenceModuleImpl muc/modules/groupchat[S]=tigase.muc.modules.GroupchatMessageModule muc/modules/invitations[S]=tigase.muc.modules.MediatedInvitationModule muc/modules/urn:xmpp:ping[S]=tigase.component.modules.impl.XmppPingModule muc/modules/unique[S]=tigase.muc.modules.UniqueRoomNameModule muc/modules/disco[S]=tigase.muc.modules.DiscoveryModule muc/modules/iqforwarder[S]=tigase.muc.modules.IqStanzaForwarderModule muc/modules/admin[S]=tigase.muc.modules.ModeratorModule muc/modules/privatemessages[S]=tigase.muc.modules.PrivateMessageModule muc/modules/commands[S]=tigase.component.modules.impl.AdHocCommandModule