Jabber

Jabber is the name used for an open, interoperable architecture for instant messaging and presence. The project began as Jabber, a decentralized protocol and network, and it is now more commonly referred to by the protocol's formal name, Extensible Messaging and Presence Protocol (XMPP). In practice, many users and products still call it Jabber.

XMPP is an XML-based, client–server and server–to–server protocol designed for near real‑time communication. It operates with XML streams and stanzas that carry messages, presence information, and information about contact lists and other data. The design emphasizes federation, allowing multiple servers to interoperate across administrative domains.

Implementation and ecosystem: The Jabber/XMPP ecosystem includes numerous servers (such as ejabberd, Prosody, Openfire) and clients (for example, Pidgin, Adium, Gajim). The protocol is extended through XMPP Extension Protocols (XEPs) to cover features like multi-user chat, file transfer, message receipts, and encryption. The network is largely decentralized, enabling federated communication between independent servers.

History: Created in 1999 by Jeremie Miller, Jabber grew into a popular open‑source project with a growing ecosystem of servers and clients. In 2004, the IETF standardized the protocol under the name XMPP and encouraged the use of the XMPP branding, though the legacy name remains widely used.

Security and privacy: XMPP supports Transport Layer Security (TLS) for encryption in transit and Simple Authentication and Security Layer (SASL) for authentication. End‑to‑end encryption is provided by extensions such as OMEMO and OTR, but its availability depends on client and server support.