Ejabberd

ejabberd is a free (GPL) distributed fault-tolerant Jabber/XMPP server and is mainly written in Erlang. It runs under Windows NT and several Unix-like operating systems such as Linux, FreeBSD and NetBSD.

Alexey Shchepin started the project in 2002 and still remains the maintainer of it. He says that the name ejabberd stands for Erlang JABBER Daemon. ejabberd is written in small letters only which is common use in the unix-world. The goal of ejabberd is to create a stable and full-featured Jabber server.

Features

Besides clustering, ejabberd also has many other features like a web interface for admins, shared roster, PostgreSQL (ODBC) support, support for virtual domains, nearly XMPP-compliance, a translated interface (including English), LDAP authentication, login via SSL, SASL and STARTTLS. It also supports modules. Most of them provide simple things like for example saving offline messages, but in contrast there are also modules which make more advanced functionalities possible: an IRC-transport to connect with IRC channels, a MUC module, a module for HTTP Polling, a user database module which makes use of user's vCards (saving vCards in LDAP is possible with another module), a module for Publish-Subscribe, and a module to gather statistics via Jabber.

ejabberd has no authentication and STARTTLS support for connections between servers.