Cambridge XMPP Sprint

This month, on August 18-19th, was held the first developer event in the XMPP community for a long time.

The idea came up at the Gulaschprogrammiernacht, in Karlsruhe earlier this year, talking with Daniel Gultsch, and JC Brand. We gathered there to work on an implementation of the OMEMO encryption mechanism for Converse.js, and Poezio. Converse.js is currently seeing the changes merged. It’s taking a bit more time for Poezio, but we’ll get there.

JC mentioned sprints organised by the Plone community, and I felt that was something we were missing for XMPP. While the XMPP summit is held every year before FOSDEM, it is often more oriented towards protocol discussions. Developer events are scarce.

I set a goal for myself to start a movement in the community, gather interested people, and work together to improve the ecosystem.

The first event – of this hopefully long series of events – was held this month, sponsored by my employer, Collabora, in their UK offices in Cambridge!

Who attended

• Daniel Gultsch from Conversations
• MattJ from Prosody
• fiaxh and larma from Dino
• Andrey Utkin from decent.im
• Link Mauve from JabberFR, and Poezio
• pep. from Poezio
• Friends and colleagues, first time XMPP contributors

And remotely:

• JC Brand from Converse.js

Objectives

We started the sprint with a short standup, to discuss ideas gathered during the previous weeks online, and to narrow the focus to a few feasible items. At this point it became clear that User Experience (UX) would be an important topic during the weekend, as it is also within the XMPP community of late.

Here is roughly what was mentioned, and what we planned to work on:

1. Bookmarks: Sync Private XML bookmarks with PEP ones.
   XMPP has different standard places to store bookmarks, and this has often proven to be a painful experience to the user, when using different clients for example. The objective here was to transparently synchronize both stores, so that the user gets an overall nicer experience.
2. Message Attaching and Reactions.
   Message Attaching defines a way by which one can indicate that a message is semantically related, “attached”, to an earlier message in the discussion. This can be useful for reactions, for example, or even for previews of links.
3. In-Band Registration in clients that don’t support it, namely Dino and Poezio.
   In-Band Registration is a mechanism that allows clients to provide an interface to create accounts on servers that allow it. This way the user doesn’t have to go through multiple hops to start chatting with their friends.
4. Consistent color generation.
   This specification aims at providing algorithms that will be used to generate deterministic colors, so that they stay consistent across clients, and thus help with recognition, for nicknames in groupchats, for example.
5. Hats.
   Hats allow for customised roles and affiliations in chatrooms, an extension of the usual roles and affiliations. They can be used as regular “titles” that are displayed to other users, (e.g., “Teacher”, “Student”, “Developer of XYZ”), but can also carry permission information. The current specification needed reworking as it has been left with lots of TODOs, and was not really finished nor implementable.

Accomplishments

Not everything that was mentioned on the saturday morning was worked on, but we did manage to get quite a few things done. This was also the opportunity to discuss about various topics.

As this is also something I would like to encourage, I am happy to say that first-time XMPP users were able to contribute on projects, by providing feedback as well as patches.

Here is a non-exhaustive list of issues/topics we worked on:

Conversations

• Use PEP Bookmarks if urn:xmpp:bookmarks-conversion:0 is announced. commit
• Experiments with Consistent Color Generation:
  Disabled by default variant that uses HSLUV instead of YCbCr. HSLUV provides more uniform colors and also ’nicer’ colors by default. commit
• Updated Conversations Compliance Checker help for Prosody: pull/6

Converse.js

• Detailed Converse.js walkthrough for all people attending, by JC himself
• Better ordering of name fallbacks: pull/1168
• Attempt at a new UI/design: pull/1167
• Almost working implementation of Discovering Alternative XMPP Connection methods: pull/1170

Dino

• Implemented SCRAM-SHA-1: tree/scram-sha-1
• Fixed NVIDIA specific rendering and performance issue
• Experiments with Consistent Color Generation
• Visually improved Sign In dialog
• Add In-Band Registration support (supports forms and OOB)
• Fixed display names in MUCs without localparts (!)

Packaging

• Added XMPP-related software to main Gentoo package repository
  • Slixmpp (Python lib) https://bugs.gentoo.org/533586
  • Poezio (console client app) https://bugs.gentoo.org/377137
  • Dino (GUI client app) https://bugs.gentoo.org/631772
• Working on adding the following projects to the Gentoo main repo:
  • Biboumi (IRC gateway)
  • Spectrum (multiprotocol gateway)
  • Swift (client and library)
  • Profanity (console client)

Poezio

• XML pretty-printing plugin: xmlindent.py
• Started implementation of In-Band Registration in Poezio!10 and Slixmpp!4
• Fixed launch script version
• Discussed about how to correctly handle xmpp URIs in Poezio

Prosody

• Bookmarks sync: mod_bookmarks
  • Updated default bookmarks for that: mod_default_bookmarks
• Started implementation of hats as a Prosody module

XEPs (specifications)

• Synchronisation between vCard-based and PEP avatars: pull/700
• Started XEP for synchronisation between Private XML and PEP bookmarks
• Message attachments XEP updated: pull/696
• Started writing of a counter-proposal XEP for Hats.

Original information about the event is now listed in the wiki.

I would like to thank everybody who participated, helped organise the event, and made all this possible. Thanks Collabora again for sponsoring the event and providing the venue.

What’s Next

Talks of organising a next sprint this year in Düsseldorf, or Paris, are already happening. I would also like to encourage anybody who wants to organize similar events in their region. If you are interested and want to help organize, or participate, please join the chatroom for more information.