Spark (XMPP client)
Spark is an open-source instant messaging program (based on XMPP protocol) that allows users to communicate in real time. It can be integrated with the Openfire server to provide additional features such as controlling various parts of Spark functionality from a central management console or integrating with a customer support service Fastpath, allowing Spark users to log in to queues, accept and forward support requests, use canned responses. Being a cross-platform application, it can run on various systems. Installers for Windows, macOS and Linux are available on the official website.

History
Previously known as Jive Communicator, it was designed by Jive Software with business usage in mind, with a lightweight graphical design and simplistic user interface. Later, it was open-sourced and donated to the Ignite Realtime community, along with Openfire, for further improvement and development.

Features
Spark is based on a popular open-source Smack API library, also developed by Ignite Realtime. It has a tabbed interface for managing conversations, a quick and full history, and a robust search inside the contacts window, which is designed for organizations with many units and employees. Other features include shortcuts to access recent and favorite contacts, and Spark supports ad hoc and regular group chats. Like most modern IM clients, Spark supports SSL/TLS encryption, and additionally provides an option to use Off-the-Record Messaging for end-to-end encryption. Though it is designed to work with XMPP servers, it can also integrate with Kraken IM Gateway plugin for Openfire, and provide an option to connect with various other IM networks.

 Lightweight graphical user interface
 Plugins support
 Support for SSL/TLS encryption
 Client restriction and control with Openfire Client Control plugin
 Integration with Openfire Fastpath Service
 Support for other proprietary and open IM protocols via Openfire Kraken IM Gateway plugin
 Tabbed conversation
 Spell checking and automated message translation support
 Platform independent
 Single sign-on with LDAP support
 Skins
 Off-the-Record Messaging support
 Privacy lists
 File transfers
 Multi-user chat support

See also 

 Extensible Messaging and Presence Protocol

References

External links 
 Official website
 GitHub repository

Java platform software
Instant messaging
Free software programmed in Java (programming language)
Windows software
Linux software
Free software
Free XMPP clients