Openfire

Openfire (previously known as Wildfire, and Jive Messenger) is an XMPP server written in Java and dual-licensed under both a proprietary license and the Apache License 2.0.

Web-based administration panel
Most administration of the server is done through a web interface, which runs on the ports 9090 (HTTP) and 9091 (HTTPS) by default. Administrators can connect from anywhere and edit the server's settings, add and delete users, conference rooms, and so forth.

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 Apache Derby or other DBMS with JDBC 3 driver) for storing messages and user details
 * LDAP connectivity
 * Platform independent, pure Java
 * Full integration with Spark

The proprietary extension to Openfire allows multiple server instances to work together in one clustered environment. This extension is now open source as well.