Symbolic Achievements -- Future of UI Icons (Design of User and Developer Experiences) Symbolic UI icons are essential to the GNOME desktop, but the *icon theme* model, relying on all-encompassing semantic naming and complex fallback logic for lookup, has become a bottleneck. This talk outlines a pivot away from the system-wide theme spec toward a model where icons are treated as modern app assets. Topics the talk covers includes: * **Direct Embedding:** Treating icons as local app resources rather than external system dependencies to ensure reliability. * **Descriptive Metadata:** Moving from rigid semantic filenames to a system of descriptive keywords and tags for better discoverability. * **GtkSvg & Animation:** Leveraging the present capabilities of GtkSvg to move beyond static paths toward interpolated transitions and SVG animation. * **Tooling:** *Stateful Smart* icons require specific tooling. Talk discuses the current status quo and paints a picture of a possible future.

From Community Need to Solution: The Story of Open Forms (Application Development and Deployment) Open Forms is a GTK4 + libadwaita-based application designed to provide a native, accessible, and offline-first form. In many educational institutions, events, and organisations,form-based workflows depend heavily on proprietary web platforms. These tools often lack offline capabilities, security, accessibility in remote areas, and proper desktop integration. The origin of Open Forms can be traced back to the Ubuntu booth at GUADEC 2025, and hence, it is only appropriate to bring it to the stage at the same time. Open Forms: 1. Support offline-first data collection 2. Integrate cleanly with the GNOME platform 3. Serve community events, LoCos, and FOSS conferences 4. Run natively on Linux mobiles without needing WiFi In this talk, we will cover: 1. Why GTK4 + libadwaita were chosen 2. Lessons learned from building the app 3. Real stories of how it is helping Ubuntu booths run smoothly 4. How conferences like GUADEC foster cross-project collaboration

SVG in GNOME (Design of User and Developer Experiences) SVG is a versatile image format and it is well-supported in web browsers and the inkscape image editor. We use it for many things in GNOME, from icons to design mockups. Recently, GTK has started to support it natively. In this talk, I will take a deeper look at the SVG format and the tools we have for it, with their strengths and weaknesses.

JavaScript in GNOME 2026, Types Types and More Types (Application Development and Deployment) It’s now mid-2026 and who doesn’t want to use types to make their medium-large JavaScript codebase easier to statically analyze? We’ll talk about some of the efforts to make it easier to write GNOME apps in TypeScript. And perhaps some exciting new debugging capabilities! Besides that, there’ll be a sneak peek of what to expect from the annual JS engine upgrade, and as usual some juicy project ideas if YOU want to get involved.

Papers: new features and future projects (Application Development and Deployment) This is the first GUADEC since Papers became a core app and this talk is an opportunity to describe the state of Papers. First, we are going to present features that were added since last year, including document signing support implemented by Malika during her internship. This comprises both initial support for manual signatures (drawing or inserting a handwritten signature image) and improvement of digital signatures. We'll walk through the design decisions, the challenges of integrating signatures into the existing Papers architecture, and what still lies ahead. Then, we are going to try to lure new contributors into Papers development with a few interesting projects that will be fun to develop! They would also be very useful for users: auto-cropping pages, a new rendering cache, built-in translations…

State of GNOME OS (Application Development and Deployment) Similar to other areas of GNOME, the GNOME OS developers would like to present the progress made during the past year and the exciting plans for the future.

Modernizing evolution-data-server (Application Development and Deployment) Evolution-data-server is one of GNOME's old pieces of infrastructure that has been chugging along in the basement thanks to the efforts of a few people. This talk is about updating e-d-s's build infrastructure and exploring its relationship to Flatpak apps. We'll also have some nostalgia, as the speaker is one of the original authors of e-d-s's calendar component. Nostalgia and furry mammals.

Some more governance (Project Organisation and Governance) Turns out that governance of a large project like GNOME is not something you can improvise in an afternoon. You get to roll it out and then figure out what works and what doesn't. As the GNOME governance is loosey-goosey already, we start with the application development platform, by describing the Platform Team, as the group that governs the various components of the GNOME software development platform, used to build GNOME itself, as well as the various projects that target GNOME.

When Porting Isn't Enough: Rewriting a Python GTK2 Application for GTK4 (Application Development and Deployment) In 2010 I built Jollpi, a lightweight text editor in Python 2 with GTK2 and GtkSourceView2. When I returned in 2025, my goal was to port it to GTK4. That assumption lasted only a few hours. GTK4 is not a newer API layer — it's a different paradigm. Concepts like UIManager-based menus no longer exist. Adapting the old code would only preserve outdated assumptions. The project was rewritten from scratch. The session covers practical differences encountered, including: transitioning to `Gtk.Application`, using `Gio.FileMonitor` for external file changes, search with `GtkSourceView.SearchContext`, inline interfaces with `Gtk.Revealer`, and GTK's CSS system. Beyond API changes, the talk focuses on a real concurrency problem: keeping the editor responsive while multiple large files load and search runs in other tabs — solved by setting `GLib.PRIORITY_LOW` for background loading while managing search state through a single shared widget. Aimed at Python-GTK developers maintaining older GTK2 or GTK3 projects.

Using Mutter as an application test framework (Application Development and Deployment) Mutter is a compositor, a library, and a remote desktop endpoint, all at once. It also sports its own test suite, including "reftests" and functional tests. In the other side of the balance, GNOME has an ever growing ecosystem of applications, all sharing the hardnesses of full UI testing, the and few existing methods are usually run by third parties and require long roundtrips before finding bugs. This talk will explore the possibility of using Mutter as a test harness for UI testing in applications' CI, in order to increase their testing coverage in a much tighter loop.

Session Save/Restore (Design of User and Developer Experiences) GNOME 51 is on track to introduce a platform-wide session save and restore framework. This is a long-requested feature that allows session and app state to be saved when the user logs out, and restored when they log back in. This talk will take a deep dive through the what, why, and how of this feature

One Daemon to Rule Them All: Cross-Desktop Credential Management with OO7 (Application Development and Deployment) OO7 is a Rust implementation of the freedesktop Secret Service that provides unified credential management across GNOME and KDE Plasma. The project includes a client library, D-Bus daemon, portal backend, and CLI tools. Offering a complete, memory-safe replacement for gnome-keyring-daemon and kwallet while supporting both major Linux desktop environments through a single codebase.

Performance profiling Mutter, GNOME Shell & apps with Tracy (Application Development and Deployment) During the 2024 GNOME STF grant, I used the Tracy profiler to investigate performance in Mutter and GNOME Shell, finding several real issues, many now fixed. In this talk, I’ll use some of those investigations to show you what Tracy can do: timeline view, statistics, plots, call stacks, memory profiling, and even profiling over LAN. I’ll show how you can integrate Tracy to your app or library written in C, C++ or Rust, so you can diagnose performance problems and get a better understanding of where your code spends time and memory.

What is a good localisation coordinator? (Community Building and Diversity) A lot of our localization teams have coordinators, but what is it to be a coordinator? What is the role and responsibility toward new and long-time contributors. This issue has raised as a lot of people asked to become team coordinators while we have no standardized process to accept them in this role, nor any process to follow when you are a team coordinator.

Let's build an app for the modern GNOME platform using C++ (Application Development and Deployment) The modern GNOME platform provides a rich set of building blocks and tools for creating apps. In this workshop, we'll build an application using GTK 4, libadwaita, Blueprint, and other cool GNOME technologies. For implementing the application logic, we'll make use of peel, the new GObject bindings for C++, which will also enable us to make use of external C++ libraries. I will go over build system set-up, various best practices, and packaging our application as a ready-to-install Flatpak. The goal of this session is to demonstrate how the various building blocks of the modern GNOME platform fit together, but also to show that making a neat app for GNOME can be easy, fun, and accessible even to someone who doesn't have a lot of background in GNOME development.

Local-First Sync and Collaboration

• Julian Sparber
• Tobias Bernard
• Andreas Dzialocha

The Reflection team will briefly present the progress on their local-first text editor app and the tech stack used (p2panda and Loro CRDT), which will hopefully be a good basis for discussions around local-first sync in GNOME apps more generally, and initial planning for a system-level sync service. Anyone with an interest in local-first is welcome, especially app developers interested in adding sync to their own app.

GNOME OS BoF Annual GNOME OS BoF

GTK local-first workshop There are now GObject bindings for p2panda wrapping the high-level API, which makes it easy to add peer2peer network to any GTK APP. In this workshop we will build a simple App from scratch or if you have an existing app we will help you experiment with integrating p2panda. Hosts: **Julian Sparber, Tobias Bernard**