Openfire is a very popular instant messaging server because of its elegance, simplicity, extensibility, and performance. The 3.4.0 version of Openfire can do clustering. It will enable you to operate Openfire on various machines that serve similar XMPP domain. Users can allow grouping right from the admin console in only a single click. The machines that run Openfire will meet instantly to create a cluster. Because of this clustering, they can obtain excellent availability and enhanced scalability.