Mattermost's company blog covers product releases, funding rounds, security disclosures, and engineering work on its open source Slack alternative.
Commenters recommend Mattermost as a self-hosted Slack alternative, with some calling it better than Slack, though one criticizes its free-version user limits.
My personal blog runs on Grav, a flat-file CMS: https://getgrav.org/
It was really simple to set up as a Docker container, it is pretty fast due to not having a backing database but instead being file based, allows for some customization in the form of plugins (e.g. RSS/Atom feeds), is themeable and also reasonably secure (as long as you consider using additional auth in front of /admin, though the admin module itself is entirely optional, you can just write blog posts with a text editor, should you so choose).
Of course, there's not much of a network there to speak of, in regards to discoverability, nor is there any kind of advertising that would give me passive income from my writing (apart from a link to a VPS hosting provider, where I get discounts on my own hosting if someone signs up). However, using your own self-hosted blog is perfectly viable nowadays, should you so choose!
Also, if you need a Wiki, some folks out there strongly recommend BookStack (https://www.bookstackapp.com/) and in regards to communication you can use Mattermost (https://mattermost.com/) or something like it. Not to detract from the actual article itself, it's just that we live in a pretty great time with plenty of options, be it cloud based ones, or self-hosted software! Heck, I even have a PeerTube instance up and running which acts as a backup for my gaming/programming Twitch stream VODs, should YouTube ever purge things on their end.
Edit: link to the root page of the blog, for a quick…
We use IRC as a central way of communication for our LAN parties, starting in 1998 and spanning at least eight directly connected party series/"brands" over all those years.
The number of attendees ranges from about 100 up to 3,500+ (German record, 2005, still holds), including roughly two dozen parties with 1,000 to 2,500 attendees.
On the orga side, we use it daily for internal discussion and notifications. Events from our own LAN party platform's [1] party web sites (accounts, orders, forum posts, etc.), internal forums, GitLab (issues, CI build results), and social media (followers, mentions) are announced there – using a combination of web hooks, RSS, Zapier, and custom tools ([2], [3]).
These days we use IRC in tandem with a self-hosted Mattermost [4] instance, a bot to bridge between both, and the option to connect to Mattermost with an IRC client. A few things like embedded images get lost on the way, though.
On the parties itself, we run a local IRC server. There is a main party channel with auto-join. Organizers are on IRC both for internal collaboration and monitoring (e.g. [5]) as well as user support.
Tournament players are required to be present in the respective IRC channels for the tournaments they participate in.
Events from the local party intranet [1] (news posts, forum posts, tournament updates) are announced on IRC as well.
A modified version of The Lounge [6] is provided as a simple, web-based alternative as part of our intranet for everyone not…
Despite their confusion as to whether they want to really support their free and open source versions (without some absurd user count cliff), Mattermost (https://mattermost.com) is quite excellent and IMO is better than Slack. For example, editor leans towards native Markdown so things like syntax highlighting with backticks work as you expect.
Their recent update removed the paywall from SSO (and unfortunately the Gitlab SSO workaround) for social logins up to 100 seats, afterwards there's an absurd per seat cost similar to its non-open source brethren. One day if needed, I plan to drop-in an SSO middleman allowing anyone to leverage their own SSO layer (which will map to the login form with username/password) to avoid the SSO limits altogether. Though good enough for my needs, and likely yours too. Especially if you're open to paying for their seats.
Focalboard team here, thanks for the comment!
We weren't aware of Open Project previously, and we're glad to hear about it.
I think you're right, Focalboard is a lot earlier than Open Project, and it doesn't have as many features.
Focalboard was starting during the Mattermost 2020 Hacktoberfest last year: https://mattermost.com/blog/hacktoberfest-2020-recap/
It's in the early stages of development, only v0.6 right now: https://github.com/mattermost/focalboard/blob/main/CHANGELOG.md
That said, we're working on it constantly and excited about its future.
Of the features Open Project has now, are there one or two top priorities you'd suggest we consider adding to Focalboard?
We'd love to hear any feedback, feature suggestions or bug reports: https://github.com/mattermost/focalboard/wiki/Share-your-feedback!
Apart from already mentioned Mattermost[0] and rocket.chat[1], Matrix[2] and their main client Riot[3] is seriously worth checking out. It's a quite ambitious effort for decentralized, federated IM / group communication. There's still some work left on the protocol in terms of federated identity, which should not be necessary of you're looking to replace Slack. I haven't spent significant time with it in the past year or so, but from my understanding it's starting to become production ready.
IMO there's value in pushing for decentralized, federated alternatives. Would be interested to hear from people who have used it in anger.
[0]: https://mattermost.com/
[1]: https://rocket.chat/
[2]: https://matrix.org/
[3]: https://about.riot.im/
At Mattermost we went for the do-it-yourself option and wrote a custom tool for the job [1]. After a lot of research on all the existing open-source frameworks we couldn't really find anything that would fit our use-case. We are quite happy with the result although, as the OP mentioned, there's a significant maintenance cost attached. As new features gets implemented and more API calls added you need to go back and make sure your user behaviour defining logic stays in sync with the real world.
If I were to do it all over again, I'd probably give k6 [2] a chance but I am still convinced a tailored solution was the best choice.
[1] https://mattermost.com/blog/improving-performance-through-load-testing/
[2] https://k6.io/