I help run the open-source Flow Battery Research Collective project. As part of that, we are trying to kick-start an open-source community around democratizing a (to-date) relatively niche, uncommon technology.
It felt a bit weird putting our project out into the big bad internet, and waiting for something to happen (okay, we didn’t just wait, we got to work and starting developing the technology and writing about it). And then some people noticed!
A lot of people reached out to us privately, over email, etc. From other projects, I’ve seen it’s good to have a common digital space for people to gather, discuss, and store collective knowledge. Back in the day, this would’ve been a mailing list, forum, or IRC channel (can’t say I was even on one of those).
Ew, Discord
The current popular mainstream option is Discord. I personally find Discord to have the user interface of a kid-height candy section at the grocery checkout (non-US folks don’t understand this reference, it’s okay, enjoy your absence of juvenile diabetes).

It was designed for young gamers IIRC, so this makes sense, but to be used for an open-source project community? If it works it works, but I don’t like it. Every time I open it up it downloads a massive update (or six):

Then, minutes later when it updates, I get popups asking me if I want to accept a quest? I open this app because I want to * checks notes * see what are the latest updates are in my local public transit advocacy group—not go on a quest for the Vessel of Hatred (exciting though as that may be?).

Needless to say I did not consider Discord as an option for our community—also because it is a walled garden, we would not own the data, it could be lost any time, etc. etc. Same goes for Slack. I’ve been in so many groups where collective knowledge is lost because the group has gone over the free 10,000 message limit and everyone is too stingy to pay for the expensive hosting option. Or things just get deleted, and you have no recourse.
We tried Discourse
Forums are coming back, though, and I had heard good things about Discourse. They offer free hosting for open-source projects, and so they graciously hosted us initially. The software was easy to use. I think it’s a bit heavy to self-host. It was a bare-bones free tier plan, which didn’t include any ActivityPub functionality (there is a plugin though).
However, included in the free tier, was a bunch of stuff like this:

I get that AI might be useful if you have a big forum with lots of users and knowledge… but I didn’t care about that at all. I just wanted people to come hang out! I had a hunch that ActivityPub might allow us to do that, since some people on Mastodon were interested in our project. I totally get that most people don’t want to sign up for YET ANOTHER account, much less on a rogue, cricket-chirping quiet open-source project forum…
Enter NodeBB!
Then I saw that NodeBB, a different open-source forum hosting software (that I wasn’t aware of before), had added ActivityPub support! Into the very core of the software! And they also host open-source project communities for free!
They understand:
Fedi-what?
Fediverse! Here’s a TechCrunch primer about it, but at the end of the day, it doesn’t really matter. All you need to know is that NodeBB plugs in to a wider social network so that you don’t have to cultivate an audience, they’re already there.
This is exactly what I wanted to tap into.
And it works! Right away, we had way more people engaging with our posts, answering technical questions about AC motor control, sharing our talk at FOSDEM… (which I also uploaded to PeerTube, another ActivityPub-enabled service).
I can now interact with the forum from my personal Mastodon account, and so can anyone else, from Mastodon or any other ActivityPub-enabled service. By boosting some forum posts, I was able to easily share the new forum with my existing connections on Mastodon, some of whom only are interested in this project. They can now follow the project directly, by following the forum topics with ActivityPub.
I also asked my colleague Daniel to enable the ActivityPub WordPress plugin for his blog—now, his blog is also part of the fediverse, and we can import his past and future posts so that they show up in the forum. I even found another existing blog with some super relevant flow battery posts, all because they too had decided to enable ActivityPub support on their blog!
I am very happy with how this experiment has gone. A robust community is key to developing an open-source technology, and this will help us achieve that.
Another fun point: NodeBB implemented this functionality with funding from NLnet, the same organization that has funded our project. One day hopefully our batteries will provide standby power to other servers running NodeBB and other NLnet-funded software (they have helped a lot of cool projects!).
Conclusion
I’d recommend NodeBB to people starting a fledgling open-source community, especially if you already have some interested folks on the fediverse, because it makes it much easier to onboard and share your project vs. a conventional, totally isolated web forum.