I and my team at The Green Land are looking for a self-hosted version of event organisation tools like MeetUp.com or Eventbrite. Both for small scale events as part of projects, such as meet-ups of citizen scientists, as well as for ourselves, such as small gatherings we organise around AI ethics with our professional peer network.

We don’t want to use Meetup.com or things like Eventbrite because we don’t want personal data to be handed over to US based entities, nor require the participants to do so just because they want to attend a local event. We also notice a strong hesitancy amongst participants of events when it is needed to create yet another account on yet another service just to let us know they will be joining us for something.

Nevertheless we do want an easy way to announce events, track registrations, and have a place to share material before, during and afterwards. And I know that events are hard in terms of discovery, because although there are a plethora of events, for most participants as well as event organisers they’re incidents (years ago I came across a blogpost describing this Events Paradox well.). Additionally, for us as professionals it is usually more logical to host our own events than find one that fits our needs.
So we need a way to announce events where we can assure participants there’s no need to hand over personal information, and where material can be shared.

There seem to be two FOSS offerings in this space. Mobilizon by Framasoft and Gettogether. In the past weeks my colleague S and I tried to test Mobilizon.

Mobilizon is ActivityPub based, and there’s a Yunohost version which I installed on our VPS early last month. Mobilizon promises several strong points:

  • Fully self-hosted, and able to federate with other instances. There aren’t many visible instances out there, but one NGO we frequently encounter in our network does run its own instance.
  • you can maintain different profiles in your account, so that for different parts of your life you can subscribe to events, without e.g. your historical re-enactment events showing up amongst your professional events in a public profile.
  • People can register for an event without needing an account or profile (using e-mail confirmation)

Working with Mobilizon turned out less than ideal at a very basic level. Accounts couldn’t log in after creation. As an administrator I could not force password resets for users (that couldn’t log in anymore). Not being able to do user admin (other than suspending accounts) seems to be a deliberate design choice.
I still had access through my Yunohost admin account, but after an update yesterday of the Mobilizon app that stopped working too. So now both instance admins were locked out. Existing documentation wasn’t much help in understanding what exactly is going on.

I also came across an announcement dat Framasoft intends to shift development resources away from Mobilizon by the end of the year, and thusfar there’s little momentum in the developer community to pick up where they intend to leave off.

For now I have uninstalled Mobilizon. I will reach out to the mentioned NGO to hear how their experiences are. And will look at the other tool, although no Yunohost version of it exists.

I’m open te hear about other alternatives that might be good to try.

The WordPress ActivityPub plugin by Matthias Pfefferle has been updated. It now allows you to @mention ActivityPub users and they will be notified of the mention in your blogpost, through ActivityPub.

This is useful. Yet, I’m holding out on using the plugin myself until three things are possible:

  • Set the user name of the ActivityPub account: Now the username is the login name of the user doing the posting. I recognise using WP user names is a straightforward way of turning WP into an ActivityPub client, and prevents having to add addditional stuff to the database. As I use non-obvious user names for additional website security, having those exposed as ActivityPub users is undesirable however.
  • Refuse follow requests: currently the plugin allows follows, and defaults to accepting all follows. As on my separate AP account I want to decide personally on follow requests.
  • Determine flexibly which postings get shared through ActivityPub, and through which ActivityPub user account. The current set-up is that all postings get shared through ActivityPub. I’d rather be able to determine not just on a post by post basis what gets shared but also to have specific categories of postings to be shared through a specific account.

I want to actively use the affordances ActivityPub allows on top of those WordPress as blogging tool provides. For me that is the ability to use the different activity types that AP can support, and to use dealing with followers and follows to selectively disclose content to different groups of people.

My current usecase for this is to have a separate AP account that shares my travel plans (posted in an unlisted category on my site) with accepted followers. The first part requires selectively sharing a category of postings, the second part doing so to a group of accepted followers on an AP account that is meant for just this type of postings and not my general AP account.

The plugin will develop in this direction, but is not there yet. I am slowly going through the code of the plugin myself to understand its architecture and choices. Perhaps it will give me an idea either on how to build on its core to create the functionality locally I want for myself, or maybe (though my coding skills are likely not adequate for it) add to the plugin itself.

In reply to How can my posts integrate better with ActivityPub? by Chris Aldrich

I’m trying to add AP to my site here to be able to provide streams to approved followers of otherwise unlisted content in my site. E.g. travel plans like Dopplr did, or Swarm style check-ins (normally posted to WP with micropub, e.g. here). Both those activities exist in ActivityStreams and thus in AP. That would be possible to follow with various existing AP clients. If more people do it, it might be useful to create a client surface to combine the various travel plan streams of others I follow and show crossing paths etc.

Peter has experimented for a while with Mastodon (and the ActivityPub protocol behind it) and decided that it’s not for him.

Well, this has been fun, but it turns out that the effort-vs-reward for the fediverse doesn’t balance for me; I need fewer reasons to be tethered, not more. @mastohost, recommended by @ton, was an excellent playground. In 24 hours this account will self-destruct. But, now and forever, https://ruk.ca is where you’ll find me.

I very much recognise his point. The disbalance he mentions I felt strongly in the past month, where it was absent in the five and a half years before it. The enormous influx of people, positive in itself, and the resulting growth in the number of people I followed made my timeline too busy. In response I started following topics more and am evaluating rss feeds from ActivityPub servers. The disbalance expresses itself in spending too much time in the home timeline, without that resulting in notable things. (I mean literally notable, as in taking notes) Unlike my feedreader. It does result in some interesting conversations. However such interactions usually start from a blogpost that I share. Because of the newness of AP and Mastodon to the large wave of people joining, many posts including mine are of the ‘Using Mastodon to talk about Mastodon’ type. This is of course common for newly adopted tools, and I still have a category on this blog for metablogging, as blogging about blogging has been a 20 year long pattern here. Yet it is also tiring because it is mostly noise, including the whole kindergarten level discussions between petty admins defederating each other. There’s a very serious discussion to be had about moderation, blocks and defederation, to turn it into a tool that provides agency to individual users and the groups they are part of. These tools are important, and I’m glad I have them at my disposal. Ironically such serious discussion about Mastodon isn’t easy to conduct in a Tweetdeck and Twitter style interface, such as Mastodon provides. I moved the home timeline over to the right in my Mastodon web interface, so I don’t see it as the first thing when I open it up. I’ve concluded I need to step away from timeline overwhelm. Much as I did on Twitter years ago.

A tired purple mastodont lies on the ground sleeping while groups of people are talking in the background, sketchbook style. Dall-E generated image.

There are however two distinct aspects about AP and the recent incoming wave of people that I am more interested to be engaged with than I was before this started.

First, to experiment personally with AP itself, and if possible with the less known Activities that AP could support, e.g. travel and check-ins. This as an extension of my personal site in areas that WordPress, OPML and RSS currently can’t provide to me. This increases my own agency, by adding affordances to my site. This in time may mean I won’t be hosting or self-hosting my personal Mastodon instance. (See my current fediverse activities)

Second, to volunteer for governance related topics in the wider Dutch user group of Mastodon. Regardless of my own use of Mastodon, it is an environment in which many more people than before have new choices to make w.r.t. taking their online presence and tools in their own hands. A step from a global silo such as Twitter to e.g. a larger Dutch instance, while not the same as running one’s own, can be a significant step to more personal agency and networked agency. I’m involved in a group discussing how to establish governance structures that can provide continuity to the Dutch instance Mastodon.nl, lets people on the instance have an active voice and role in its internal governance, and raises awareness of the variety of tools and possibilites out there while purposefully avoiding becoming a new silo (through e.g. providing pathways away from the instance). Such governance is not part of the Mastodon instance, but structured around it. Such involvement is an expression of my experience and role in using tech for the past 33 years online as being inherently political.

A purple mastodont is conversing with a crowd of people, sketchbook style. Dall-E generated image.

Brief overview of how I’m active in the fediverse.

My site

I would prefer this site to be the centerpoint of my fediverse presence. For now that isn’t fully feasible, but it will be over time. Already the building blocks for WordPress to be a fediverse actor exist. The Activity Pub (AP) plugin and Webfinger plugin by Matthias Pfefferle are useful, just not allowing enough granular control yet to my taste. For one, the AP plugin exposes actual usernames of my WP site, a disclosure I don’t like. I need to be able to set the actor names for AP, through the AP plugin and/or the Webfinger plugin. Second, the AP plugin allows sharing my blogposts but only all blogposts, and I want to be able to only publish certain categories of posts as well as individual posts marked for sharing through AP. Third, the AP plugin doesn’t yet take into account the interaction parts of AP (like follows etc.).


I run two Mastodon instances, one hosted at Masto.host. Masto.host has been a very reliable service since I started hosting with them in 2018. I ran a personal instance (m.tzyl.nl) with them until late November 2022, and started one for my company (m.tgl.eu) early November 2022. I run my personal instance of Mastodon on a VPS with Yunohost, at m.tzyl.eu

Discoverability hack

I have added simple text files to /.well-known/webfinger to both this site and my company website that allow discovery of my existing Mastodon profiles through my site’s and work e-mail addresses. This is just a hack, and I should replace it with actual functionality to disclose actors on both those sites.


Bookwyrm is the book reading application on AP. I have an account at the primary instance and supported them financially for a while, but haven’t used it much since spring 2022. This is one of the things I want to do myself through this site.

Potential AP projects

As said above I’d like to be able to share my reading through AP from this site. I would also like to be able to share my planned travel and/or check-ins through this site in AP. Specifically travel plans (Dopplr like) are of interest to me. AP, unlike this site, would allow non-public sharing of this information to followers only.

I hadn’t really looked, but it turns out that Mastodon has incorporated microformats. It has h-feed and h-card, h-entry (a status), and h-cite (a boost). Plaint text properties (p-), e-content, and link properties (u-) are implemented. Indeed, they all surface when looking at a profile’s HTML source. This is what makes it possible to e.g. follow Mastodon feeds as h-feed, next to the existing RSS output and ActivityPub, and that e.g. Brid.gy can do its work to carry over any interaction on a Mastodon post to a blogpost here.

What I haven’t found was what I was looking for.
The ActivityPub protocol in its specs has several so-called Activity Types that drew my attention:

In short ActivityPub supports FourSquare and Dopplr like check-ins and travel plans. I’ve recently added that to my site in terms of microformats and was still wondering how to create a useful stream for it. I’ve been thinking about an OPML outline with schema.org attributes, or a dedicated RSS feed or h-feed. An ActivityPub stream might be of interest too, or even more. There’s a PHP implementation of ActivityPub that includes these Activity Types as well, meaning there’s potential to experiment for me.

I wonder, are there any actual implementations of these ActivityPub types currently?