ejabberd is free software, distributed under the terms of the GNU General Public License. As of 2009, it is one of the most popular open source applications written in Erlang. XMPP: The Definitive Guide (O'Reilly Media, 2009) praised ejabberd for its scalability and clustering feature, at the same time pointing out that being written in Erlang is a potential acceptance issue for users and contributors. The software's creator, Alexey Shchepin was awarded the Erlang User of the Year award at the 2006 Erlang user conference.
With the next major release after version 2 (previously called ejabberd 3), the versioning scheme was changed to reflect release dates as "Year.Month-Revision" (starting with 13.04-beta1). It was also announced that further development will be split into an "ejabberd Community Server" and an "ejabberd Commercial Edition [which] targets carriers, websites, service providers, large corporations, universities, game companies, that need high level of commitment from ProcessOne, stability and performance and a unique set of features to run their business successfully." 
ejabberd is extensible via modules, which can provide support for additional capabilities such as saving offline messages, connecting with IRC channels, or a user database which makes use of user's vCards (saving vCards in LDAP or an ODBC compatible database is possible with other modules).
In addition, modules can provide support for extensions of the XMPP protocol, such as MUC, HTTP polling, Publish-Subscribe, and gathering statistics via XMPP.
Starting with version 2.0.0 ejabberd also includes support for the Proxy65 file transfer proxy which enabled Jabber/XMPP users behind firewalls to share files through a SOCKS 5 proxy.
ejabberd can communicate with other XMPP servers and with non-XMPP instant messaging networks as well, using a special type of XMPP component called transport or gateway.