( = Extensible Messaging and Presence Protocol,
"laiendatav sõnumivahetuse ja kohalolu protokoll")

olemus
XML-põhine kiirmeili ja kohaloluteabe protokoll, mis toetab ka failide, kõne, video edastust; ei sõltu operatsioonisüsteemi ega brauseri tüübist
= a communications protocol for message-oriented middleware based on XML

ülevaateid
https://en.wikipedia.org/wiki/XMPP
https://www.cometchat.com/blog/xmpp-extensible-messaging-presence-protocol
https://getstream.io/blog/xmpp-extensible-messaging-presence-protocol/
https://xmpp.org/about/technology-overview.html
https://community.element14.com/learn/learning-center/the-tech-connection/w/documents/4149/the-xmpp-protocol-benefits-architecture-and-applications
https://www.blazeclan.com/blog/xmpp-for-dummies-creating-your-own-chat-application-from-scratch-part1/

standardid
https://tools.ietf.org/html/rfc6120
https://tools.ietf.org/html/rfc6121