My earlier career was as a particle physicist in CERN. We identify four fundamental forces in physics:

• electro-magnetism
• weak interaction
• strong interaction
• gravitation

We have the quantum theory to explain three of them. In 2012 at CERN we discovered the Higgs particle using the Large Hadron Collider at CERN.

Gravity was discovered in the 17th century. It got replaced by Einstein's general relativity. This is poorly tested. Central are gravitational waves.

Einstein: gravity is not a force, but is a curve in space and time itself. If it is curved, it should be possible to create ripples in it. This is similar to electro-magnetism. Gravitational waves are generated by movements of mass: if I shake this pointer, technically it will create tiny gravitational waves. Einstein made a prediction about gravitational waves, but said they could probably never be measured.

If you have two black holes that circulate around each other, they generate gravitational waves. They lose energy because they generate those waves. They collide, become one black hole, and stop. Then the gravitational waves also stop being sent. Eventually these waves will reach the earth. Detecting them requires precision.

Compare: take the Mediterranean Sea, add one drop of water, and the wave this generates is comparable to the effect of a gravitational wave.

Observation GW150914 was the first: two black holes of 36 and 29 solar masses merge into a single black hole of 62 solar masses. 3 solar masses were converted into gravitational wave energy. The most energetic event ever measured. Since then, we measured about 400 of these events.

Current detectors observe about one signal per week. We want to build the Einstein Telescope (ET). This will detect about 100 thousand to 1 million mergers of black holes per year, is the expectation. Current detectors are until about 4 kilometers, the ET will be about 10 kilometers.

If you observe a wave, you look into the past. The oldest black hole observed, is from at most about 6 billion years ago. With the ET, we could look all the way back to the Big Bang. So it is really in this sense the ultimate telescope: there is no sense in building an even bigger one, because we will already be able to see everything.

The overal structure of science related to this in Europe is a board of governmental representatives, then the ET project organisation, site organisations, and ET collaboration. There is competition for three spots to build the ET: Italy (Sardinia), the region at the border of Germany and Poland (Saxony), and the region where you are now, in the Maastricht region, or EMR (Euregio Maas-Rhine).

We don't know yet how we want to build it. There are two promising geometries: a triangle, or two L-shapes. Nice thing about the triangle, is that you can really do this in a way that you can have three L-shapes hooking into each other, in the same tunnel. With two L-shapes, one L would need to be in Sardinia, and the other either in the Maastricht region or in Saxony.

ET project timeline: in October there will be a decision on which geometry to use. In december there is a call for tenders, open for half a year, and in third quarter next year the final decision of location (or locations) will be made.

In the ET we want to lower the frequency that we can detect from 40 Herz to maybe as low as 8 Herz. The lower you can get this, the longer the period you can hear and study an event: at 40 Herz it was half a second, at lower frequencies it can be half an hour. Here in Maastricht we are researching the low-frequency challenge, with ETpathfinder.

We have a special geological environment in this region. The top layer is quite soft, but below is hard rock. Vibrations made by man and nature are absorbed by the soft top layer. We made many drill holes to find the optimal location. The triangle will be completely in Belgium, in Wallonia. We are developing the models needed to predict how the site will affect the telescope.

Martin Peeters: Plone Foundation membership

If you are a Plone Foundation member, make sure you have renewed your membership. If not, talk to an admin. And you should have received an email allowing you to vote in the Foundation Board election.

Mack Palomaki: Aurora

I helped a musician, Salamon Jakobsson with a Plone site (Aurora on Nick), and in thanks and answer he wrote a piece of music called Aurora. Hear him explain about it, and then play it: https://salomonjakobsson.ljusa-tider.se

Astrid: Coffee disloyalty

In my town there is a new coffee shop each week. You wonder how they make any money. They are not dependent on early adopters, everyone already knows what coffee is.

Last year after the Plone Conference we were in Helsinki. It was during the Helsinki coffee week. At a coffee shop we got a disloyalty card. Not loyalty, but disloyalty. Go to a different coffee shop and you get another sticker. The sixth coffee is free.

This got us all over Helsinki.

Sometimes you just need to be relaxed, and confident.

David Glick: Recycle bin

I want to look at (my) software and want to see the beauty and the thought that was put into it.

But in Plone code you often see very old TODO comments from before a first release. Or a PLIP from seven years ago: Plone should have a recycle bin.

Now we have plone.recyclebin. You delete something, everything happens as normally, but a reference is kept. Lots of credit to Rohan Shaw who worked on this last summer. Various people reviewed it. I took time this summer to finish it, and last night I pushed the button.

Now go and use it production, and give feedback.

https://github.com/plone/plone-recyclebin

Franco: collective AI settings

Control panel for configuring a connection to an AI backend. Local or remote. You can add several models. See https://github.com/collective/collective-ai-settings

There is another package with tools that use this. When editing a page in Plone you can ask it to create a summary, or write a text. On an image you can ask it to suggest tags, description, etc. See https://github.com/collective/collective-ai-tools

Jens Klein: Doc style skill

I let AI write some documentation for Plone, but got feedback from Steve about things that were wrong with it. So I created an AI skill, based on the documentation that we have about writing documentation. Try it, it helps. See https://github.com/plone/plone-doc-style-skill

Torben Baumgartner: Show my setup: Pylon and split

Pylon is a VS Code MCP Server. See https://github.com/toalba/Pylon

And split is a proxy, that I cannot share, that can direct queries to other LLMs.

Armin: Social media engagement boost to save Plone's future

The LinkedIn Bell. For Plone to survive it should be recognized. How can you personally boost Plone? What we have is media assets: text, images, media. What we miss is range and attention.

Change your behavior, tiny habits, find the trigger. Click the bell on the Plone page on LinkedIn. Click it, and select Everything, instead of only the most important.

If you have a nice story, say from the Plone conference, share it. Then others who have clicked the bell, can see this too, and their network sees it.

Rikupekka: next.plone.org

We have been working on the next plone.org website this year. Check out the video. And join the sprint this weekend.

Armin: Show your setup: Digital KungFu

Automator is an app that is standard on Mac. You can create an action with it to run a Python script on hotkeys on the Mac. Or on iPhone.

Johan: The back of the badge

The conference badge half of the time has the blank side on the front. Please grab a pen and write something on the back of your badge.

Antoine: Plone 4 to Plone 6, make no mistake

You can try migration using agentic coding. Make no mistake: well, make mistakes, but make sure to not make the same mistake twice. Design feedback loops: have a goal you can check, give feedback fast, improve.

Loop 1: Write your migration into a big plan. Let AI turn it into smaller chunks.

Loop 2: Unit test loop: run the tests, they fail, fix one thing, run the tests. Small steps.

Loop 3: The design loop. Take the design, the AI agent builds it, compare, repeat. Whenever the AI made mistakes, we had it write a rule.

60 hours of Claude running, about 4 billion tokens consumed, on a single Claude 5x plan.

You still need a human to set goals, and give early feedback.

Alexander Loechel: Terminal status panel

Probably people often come to you with their problems, because you are a smart person. But we are lazy, and want to get something quickly done.

Something goed wrong on a server. What is the status? We developed something in house, published it as a tool. If we log into a server, in a separate terminal it shows the status of the server, all kinds of information. And you can just click some URLs in the the text it shows in the terminal.

See https://pypi.org/project/terminal-status-panel/

Do we own our digital past?

Quote: Those who cannot remember the past, are condemned to repeat it.

Twist: Those who do not document and publish their past, will only remember AI-generated summaries of their past.

Three inspirations (people): Christine Baumgartner over beers in Austria at sprints, Astrid Beyers to whom I gave a speed-history of Plone, and Sally Kleinfeldt. Other inspirations: Stellenbosch Sprint 2026, reconfirm core values. Jon Cherry: Information does not need to be on the homepage, but "information should be diggable."

If we don't act 'soon', this diggable information will disappear: we have started storing things on SAAS platforms, we may lose credentials or people retire, information may disappear in plone.org renewals. We have limited resources, and have a complex past, present, and future.

It is against our nature: we tend to look forward (and plan for some maintenance). Song by Bastille: Give Me the Future. New people still come into the Plone project, and they want to know: what happened before. What were the crazy ideas of the past. I can write a story, but it will be my story, the story of a by now grey haired white male from Europe. I have no idea of lots of things that happened in South America or Asia.

More serendipity: find things you didn't seek. Can we get a blogs.plone.org where people put their Plone-related stuff and the Plone community maintains it. I asked AI, and after a lot of back and forth, and at the end it said: eat your own dog food, just use Plone. We have tools like pas.plugins.identity and collective.multiworkflow that Érico is working on, that help here. Erico wrote https://ericof.com/en/posts/2026/plone-archeology-2003-2012 showing screen shots of old versions of Plone.

We can create The Little Book of Plone. Plone website. If we gather everything, it is too much: 2000 pages? You need to curate it: what is most important? Can we have a slider at the top, to have three levels:

• verified/agreed short history
• extra background info, still checked
• media, personal stories

Invite contribution. Central Identity Management to log in. Conservation and backup should be the responsibility of the foundation and community. And start collecting stories, for real!

But is this a "book"? I don't know, yet. But it is story telling. Future marketing.

Astrid, Cihan: Each year we could have a small exhibition at the Plone conference, with stuff people bring.

Armin: Create a Plone distribution for organisations for an archive. Then we don't do it only for us.

My first migration was from Plone 2 to Plone 3. I will talk about migrating from Classic Plone to Volto.

Common problems with migrations:

• A run can take fours, sometimes even days, and during the run you see nothing. You only know the results at the end. The editors may already want to start editing on the new site before the migration has finished.
• You never migrate only once. You do test runs, make fixes, there is new content in the old site. Every step must be safe to repeat.
• After twenty years of editing in the site, not every page with html may be correctly translatable to Volto.
• Nobody can check every page, if a site has many thousands of pages. How do you know that the content has arrived?

What we need: monitoring, reliability, comparison of old and new content. So we created orchestration with a migration monitor. This runs every step, and keeps the files between the steps. It shows the run in the browser.

The source is classic Plone. A project-specific add-on defines the export steps. Then we convert html to Volto blocks. Then we import in the new site. Finally we finish, with things like setting default pages, updating links, dates, catalog.

Each step shows its progress, can be stopped, can be repeated.

During conversion to Volto blocks, if some html cannot be converted, we include this literally in an html block, so nothing gets lost. Then we report, for example: 115 out of 330 pages have no html blocks, or the html blocks contain this many characters. Comparison: show old and new page next to each other so you can visually inspect.

The tool uses websockets and FastAPI in the backend.

Demo time. (Very nice!)

If you plan a migration, talk to us. Currently the quality is good for internal usage, but we are not yet ready for releasing it.

One team, one goal, two projects. We have Plone Volto and Plone Aurora.

Plone Volto is Volto 19 and future ahead. Modernized, up to date dependencies, stable, batle tested.

Plone Aurora is bleeding edge, alpha. Based and leaning on Volto foundations, a simplified stack, standard based, and developer experience friendly.

First the state of Volto 19. This was 19 months of work, released earlier this year. We are at Volto 19.4 meanwhile. We modernized the foundation, build system, test stack, overhauled the dependencies. It became more stable, which is what we want from Volto.

Also new features.

• You can deploy it under a sub path of your domain: https://demo.plone.org/next
• Auto-save: if you close your tab, or connection goes down and you get back, you get the chance to restore the auto-saved contents.
• A Blocks control panel: how many times is which block used?

Thanks as lot to Wesley who is maintaining things in sync between Volto 19 and 18, fixing things and backporting fixes.

There were 70+ contributors to the Volto 19.x line. 203 features and bigfixes shipped. 38 alpha releases before the final.

Volto 19 is stable and supported. Today: Volto 19 is Plone 6.2, and should be your choice if you start a project today. What's next: bug fix and security support, new features. We welcome contributions. We will continue as we have done before.

There is no Volto 20 alpha yet. Why? Because we still have no breaking changes. As soon as we have that, we will make a 20 alpha.

Why would you support both Volto and Aurora, are you nuts? Yes we are. But the foundation for both is the same. The projects cross-pollinate. The basis is libraries like plone/registry. We make it easier there to register a new block, and this is used by both Volto and Aurora.

How was Aurora born, and why? React 19 is stable, server and client data fetching is solved, and tooling matured, also a new React Router version. It is built on today's practices. We answered the question: if I would rebuild Volto today, how would that look? We are striving to not make this a big migration.

We wanted a different repository to make things technically easier for us, and enabling development of the two projects at the same time. The name Aurora was chosen at the Beethovensprint this year.

Work happened during 14 sprints the past two years. If you haven't been to a sprint yet, please do. This is where a lot of development happens. But also people, good food, old and new friends, maybe karaoke.

The demo is here: https://aurora.demo.plone.org Documentation: https://plone-aurora.readthedocs.io

What is the tech foundation?

• Rendering: React 19.2, React Router 8.2 in framework mode, Vite 8
• State and data: no more Redux, as we did not need it anymore. React Router loaders/actions, shared app sate using Jotai, plone/client library
• Type-script native
• The backend API is not exposed. @plone/client talks to Plone server-side. The browser never knows where the backend lives.
• Modular monorepo
• Standards-based CSS

The game changer is the Plone Aurora editor. This is a modern block-based layer editor built on Plate.js, which itself is built upon Slate.js. We let Plate handle all blocks. We are considering plugins, like for adding comments, suggestions, collaborative editing.

The road to 1.0.0:

• Working on the theming story
• Polish the CMSUI views
• Complete the missing blocks
• i18n

Please try it, read it, break it, build it with us. Come to the next sprint. Issues are open: https://github.com/plone/aurora/issues

Questions:

What about Semantic UI? In Aurora we don't use it. In Volto 19 we still have it, but we don't use it for new things.