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Presence & ProtocolAn independent guide to Jabber and XMPP
A network operator’s desk at night, a wall of patch cables and a terminal showing a stream of short messages.

An independent guide to Jabber and XMPP

One address, one stream, one open standard

Jabber grew up in 1999 as an XML streaming protocol, went to the IETF in 2002 and became XMPP. This site explains what survived, what changed and what still works, from the RFCs rather than from memory.

Edition 2026 · Protocol · History · Servers · Clients · Standards

01-05The five layers of the guide

Five ways into the same protocol, from the shape of a stanza to the process that turns an idea into a published extension.

  1. A printed protocol specification open on a desk, passages underlined in pencil.

    01

    Protocol

    Message, presence and IQ: three stanzas carry everything else.

  2. A stack of early-2000s printed mailing-list threads and conference notes on a table.

    02

    History

    What happened, in what order, with the dates the XSF publishes itself.

  3. A small rack-mounted server in a home office, status lights on, network cable plugged in.

    03

    Servers

    Federation is the whole point; it is also the part people get wrong.

  4. A phone and a laptop side by side on a wooden desk, both showing a plain chat window.

    04

    Clients

    Two clients on the same network can behave like two different products.

  5. A whiteboard covered in a numbered process diagram, marker still in hand.

    05

    Standards

    A number is not a promise: the status line next to it is.

THE INDEXEvery essay, by date

Everything the guide has published, newest first, with the date it was written.

  1. A desktop chat client window open on a profile page showing a small looping avatar image.

    · Clients

    What a client does with an animated avatar

    The network carries the picture once; what your contacts see afterwards is decided in the client, not in the protocol.

  2. A person pausing at a garden gate on a quiet residential street, looking along the row of houses.

    · Clients

    Choosing where your account lives

    The app is the furniture. The server is the address, and the address is harder to move.

  3. A small FM antenna mounted on a rooftop mast above a residential street at dusk.

    · History

    What community radio teaches a federated network

    Long before a small XMPP server asked who may run a node, low-power radio was answering the same question on the airwaves.

  4. An old rack-mounted server in a dim equipment room, a single status light still glowing.

    · History

    Digital archaeology on a dead protocol

    A protocol twenty-seven years old has a topsoil of living documents and layers of dead ones beneath it. The dead layers still explain the surface.

  5. A printed RFC document on a library table with passages underlined in pencil.

    · History

    Reading the RFCs the way a historian reads a speech

    Most of what is said about the protocol was said by someone who had not just read it. The documents are short, public and worth more than the summaries.

  6. A sticky note with a handwritten domain name beside a laptop showing a table of DNS records.

    · Servers

    A server starts with a name: domain and DNS first

    Every guide to running a server begins with the software. The dependency nobody lists comes earlier: a name that resolves.

  7. A wall calendar above a home office desk, a small server with status lights below it.

    · Servers

    A server is a household: the weekly maintenance round

    The daemon is the visible part. What keeps it running is a boring list, done on schedule, in the right order.

  8. Two laptops on a workbench, one showing a failed connection log, a cable tester between them.

    · Servers

    When two servers stop talking

    The message did not arrive. Everything after that sentence is diagnosis, and diagnosis has a correct order.

  9. A printed list of blocked domains beside a notebook of dated incident notes on a desk.

    · Standards

    When a blocklist bans a name, not a behaviour

    Every blocking tool in the protocol answers one question: are you refusing what this address did, or what this address is?

  10. Three brass letter slots of different sizes set into a dark painted wall, photographed straight on.

    · Protocol

    Message, presence and IQ: the three stanzas

    Everything an XMPP client does is built from three XML elements. Knowing which one carries what explains most of the rest.

  11. A green painted front door seen close up, with a brass letter slot, a bell push and a worn handle.

    · Protocol

    How a JID is built, and what breaks it

    An XMPP address looks like an email address and is not one. The differences are written down, and they matter.

  12. A hand ticking names on a printed contact list, several rows already marked, desk lamp lit.

    · Protocol

    Presence, rosters and the subscription dance

    Presence is not a status message. It is a routing decision the server makes on your behalf, from a list you own.

  13. A long paper timeline taped across a wall, years written in marker, notes clipped along its length.

    · History

    From jabberd to the XMPP RFCs: a timeline

    Not quite six years separate a personal announcement from an IETF Proposed Standard. Each step is dated, and each one changed something.

  14. A brass rubber stamp and its ink pad on a leather desk blotter, lit from one side.

    · History

    Who owns the name Jabber

    Two names, two owners, one network. The confusion is old, documented, and easy to clear up.

  15. Three small servers lined up on a workbench, each with a different handwritten label taped on.

    · Servers

    ejabberd, Prosody, Openfire: how they differ

    All three speak the same protocol. Choosing between them is a question of what you are willing to operate.

  16. A terminal window on a dark screen showing a short list of DNS lookup results, keyboard in shot.

    · Servers

    The DNS records a federated server needs

    Most federation failures are DNS failures. The records are short, the rules are written down, and the order matters.

  17. Two patch cables crossing on a grey panel, connectors in focus, port numbers printed beneath.

    · Servers

    Encryption on the wire: c2s, s2s and TLS

    A message crosses at least two connections. They are secured separately, and only one of them is under your control.

  18. A closed laptop on a kitchen table beside a mug and a pair of reading glasses in morning light.

    · Clients

    What to check before you install a client

    Two clients on the same account can behave like two different products. The difference is a short list of extensions.

  19. A phone face down on a table next to a battery pack and a short charging cable, evening light.

    · Clients

    Why mobile XMPP is harder than desktop

    The protocol assumes a connection that stays open. A phone assumes the opposite. Everything else follows from that.

  20. A marker pen resting on the empty tray of a blank whiteboard in a quiet, well lit meeting room.

    · Standards

    How a XEP becomes a standard

    The number on an extension tells you nothing. The status line above it tells you almost everything.

  21. An empty meeting room with chairs pulled around a table and a screen showing a blank chat window.

    · Standards

    MUC and MIX: two answers to group chat

    Group chat was bolted on twice, twenty years apart, and the second attempt starts from a different idea of who a member is.

  22. Two identical brass keys on a dark cloth, one slightly out of focus behind the other.

    · Standards

    OMEMO and end to end encryption

    Transport encryption protects the hops. End to end encryption protects the message. They are not the same promise.

  1. A long roll of continuous paper feeding out of a teleprinter onto a wooden floor, seen from above.

    The reference page: message, presence and IQ

    Three stanza types carry everything else on an XMPP stream. Every other essay on the site comes back to this page, because every feature is built from these three shapes.

    Layer 01 · Protocol

Presence & Protocol is written by a small editorial desk, not by the XMPP Standards Foundation and not by the owner of the Jabber trademark; how we work and what we check is set out on the about page. If you read one thing first, read the reference page on the three stanza types, then come back to the protocol layer for addressing and presence.

ELSEWHEREOther desks, other fields

Pages this desk reads for method rather than subject: different fields, the same habit of writing things down.

A protocol is not the only thing kept alive by a local scene: the Cincinnati bop and swing guide documents a dance, its ballrooms and the people still keeping the floor.

Operational judgement scales up as well as down: the shipping analysis at Eitzen Group reads vessels, fuel and regulation the way an operator reads a fleet.

On the same question of how independent services get found without a platform behind them, organic visibility is the subject of Happy Traffic, a one-desk magazine on the channels that carry visitors and what each one costs to scale.

Some infrastructure fits in a pocket: the paracord knots and projects at Paracord Central are catalogued with the same care a good specification deserves.

Documentation first is a method that travels: the incident journal approach at Paranormal Help starts a strange household experience with what is known, not with what is feared.

Craft traditions have their own specifications: the workshop crafts of St Petersburg, matryoshkas, lacquer, amber and lace, are catalogued as heritage at The St. Petersburger.

A name carved in stone is a record too: the Tadcaster war memorials are followed from the monument back to the soldier’s file.

And chance has a material history: the Cabinet of Chance traces games of hazard from Mesopotamian lots to the Paris wheel.