sentence: features openfire supports the following features : web-based administration panel plugin interface customizable ssl/tls support user-friendly web interface and guided installation database connectivity ( i.e. embedded hsqldb or other dbms with jdbc 3 driver ) for storing messages and user details ldap connectivity platform independent , pure java full integration with spark im client can support more than 50,000 concurrent users the proprietary extension to openfire allows multiple server instances to work together in one clustered environment .