Online / 6 & 7 February 2021


Building massive virtual communities in Matrix

or... Spaces: The Final Frontier!

Matrix ( is an open protocol for secure, decentralised communication - defining an end-to-end-encrypted real-time communication layer for the open Web suitable for instant messaging, VoIP, microblogging, forums and more. We provide the open standard and open source tools to democratise communication away from the proprietary closed communication silos (Slack, Discord, Telegram, WhatsApp etc) that currently dominate.

In this talk, we'll explain all the features we've been adding to let Matrix scale to support massive virtual communities such as FOSDEM itself, Mozilla, KDE and others. This includes Spaces: the ability to group rooms into a hierarchy, for ease of discovery and management; Widgets: the ability to add arbitrary webapps to chatrooms to provide dashboards of additional functionality (e.g. the FOSDEM livestreams and video conferences); Threading: the ability (at last!) to support threaded conversations in Matrix; and Decentralised Reputation - the ability to empower users to tune out content they dislike on their own terms. Our goal is to ensure no open source project ever uses Slack/Discord/Telegram to collaborate ever again. Finally, we'll give a quick tour of the FOSDEM-specific work we've done in order to run FOSDEM 2021 on Matrix!

Matrix has always been built to support large virtual communities - after all, Matrix itself and all its dependent projects are developed via Matrix. Over the last year this has expanded further, with Mozilla joining Matrix in March 2020, Gitter joining in October - and meanwhile a huge influx of large virtual events and educational and public-sector deployments driven by the COVID-19 pandemic. As a result, lots of our work in 2020 has been focused on improving features for navigating and managing large virtual communities, whether that's improving the user experience in Element, or adding entirely new features to the protocol. We'll give a tour of what we've been doing, and how we deployed it for FOSDEM. We'll also show off our brand new Spaces implementation (the ability to group rooms into a hierarchy).

Spaces are particularly interesting because they open up the possibility of Matrix being more than just a big flat namespace of conversations: instead they provide a global fully decentralised hierarchical filesystem, complete with decentralised ACLs, allowing users to publish and curate an arbitrary taxonomy of whatever data they choose (be it real-time conversations, history, data streams, files, objects, etc). This has potential to flip Matrix entirely on its head: Spaces could become the main backbone of the protocol, with chatrooms being mere leaf nodes in a giant tree of collaboration. Imagine if NNTP, AFS, IRC and the Web had a baby :D We'll dig into these ideas and more, and their implications for large-scale decentralised open source collaboration in years to come!


Photo of Matthew Hodgson Matthew Hodgson