Julian Sparber

Matrix (https://matrix.org) is an open protocol for secure, decentralised communication - defining an end-to-end-encrypted real-time communication layer for the open Web. Historically the network has been made up of newly written native Matrix clients, or bridges to 3rd party existing chat systems (e.g. Slack, Discord, Telegram).

The matrix-rust-sdk is a modular Matrix client library, meant to be a robust implementation of the protocol, and to make even the most advanced features such as E2EE easy to use. This talk will walk you through the design decisions and the tradeoffs that come with it, give you an overview of where we're at and where we're going with Web-Assembly, and finally what the future holds for the matrix-rust-sdk. Finally it will be connected to a real-life example of software using the matrix-rust-sdk: Fractal-Next.

Matrix (https://matrix.org) is an open protocol for secure, decentralised communication - defining an end-to-end-encrypted real-time communication layer for the open Web. Historically the network has been made up of newly written native Matrix clients, or bridges to 3rd party existing chat systems (e.g. Slack, Discord, Telegram).

The matrix-rust-sdk is a modular Matrix client library, meant to be a robust implementation of the protocol, and to make even the most advanced features such as E2EE easy to use.

It's a flexible library which can be used both to extend existing projects or to create new ones. It is notably used in the 18 years old IRC client WeeChat to teach it to speak Matrix. It has also been used as base for the re-write of GNOME's Matrix client Fractal.

Thanks to its very modular nature, clients can either use the whole SDK, like WeeChat and Fractal do, or a sub-component. Element R uses matrix-rust-sdk's crypto crate via Kotlin bindings.

This talk will walk you through the design decisions and the tradeoffs that come with it, give you an overview of where we're at and where we're going with Web-Assembly, and finally what the future holds for the matrix-rust-sdk. Finally it will be connected to a real-life example of software using the matrix-rust-sdk: Fractal-Next.

Fractal is a popular Matrix chat client for the GNOME desktop which has been in development since 2017. Fractal was designed to work well for collaboration in large groups, such as free software projects. For a long time there were two main areas that needed improvements: performance and maintainability were limited. What’s more, it lacked end-to-end encryption (E2EE) support.

Over the course of 2021 we spent countless hours rewriting Fractal from scratch and now we are close to the first release. Fractal-next is built on top of the matrix-rust-sdk, a set of libraries that help to build Matrix clients. The client, still written in Rust, now uses GTK4. During development, the focus was on performance, maintainability and E2EE. And of course, we kept mobile support.

Teleport is an app for quickly sending files on the local network. It is designed with user experience in mind and to integrate nicely with GNOME. I'll talk about my journey developing Teleport, my first GTK app, in collaboration with Tobias Bernard.

Teleport is an app for quickly sending files on the local network.

Sadly, sharing files between two computers in the same room is still an unsolved problem in 2017. Of course there's USB keys, shared network folders, cloud storage services, and messaging apps, but they all have severe drawbacks in terms of speed, privacy, or user experience. The Apple ecosystem has AirDrop to cover this use case, but there is nothing comparable to it on GNU/Linux.

That's what Teleport is trying to fix: It offers a dead-simple interface for what should be a dead-simple task: Open the app on both machines, choose a file, the receiver gets a notification, the file is sent.

Unlike many FOSS apps, Teleport is design-driven. A designer was involved from the very beginning, and the entire app is built around providing a great end-user experience.

Teleport is a fully native GTK+3 app written in C, and integrates seamlessly with the GNOME desktop. Thanks to Flatpak, you can already use it on most GNU/Linux distributions [1].

I'll talk about my journey building this app (my first GTK app) from scratch, my collaboration with Tobias Bernard, the designer on the project, and my experience with the documentation and developer tools for the GNOME platform.

[1] http://frac-tion.com/teleport-flatpak