Practically every SaaS tool in daily office use has an open-source alternative you can run yourself: Nextcloud Talk or Matrix instead of Teams, OpenProject or Plane instead of Jira, Outline or Docmost instead of Notion, plus Mattermost instead of Slack and RustDesk instead of TeamViewer. The interesting question is a different one — which switches are worth the effort, and who looks after operations afterwards?
Why the question comes up at all
It usually starts with the subscription bill. Per seat, per month, per tool — each line looks harmless on its own, and at year’s end there’s a sum that would fund infrastructure of your own. Strikingly often, though, the push doesn’t come from money at all but from the question of where the data actually sits: knowing that project plans, internal documentation and every single chat message live with US providers has felt wrong to a lot of people since the debate about digital sovereignty picked up.
The third reason only shows itself when you try to leave. With five years of company knowledge inside Notion or Confluence, you negotiate the next price increase from a very weak position — and the EU Data Act helps less with that than many hope. Export features rarely give you back what you put in over five years.
What replaces what?
| SaaS tool | Open-source alternative | Note |
|---|---|---|
| Microsoft Teams (chat, calls) | Nextcloud Talk, Matrix/Element | Talk is the obvious pick if Nextcloud runs already; Matrix adds federation |
| Slack | Mattermost, Rocket.Chat | Mattermost feels instantly familiar to Slack users |
| Jira | OpenProject, Plane | OpenProject for classic PM, Plane for lightweight boards |
| Notion / Confluence | Outline, Docmost | both cover wiki + documentation, Markdown instead of database magic |
| OneNote / Evernote | Joplin | end-to-end encrypted sync available |
| TeamViewer | RustDesk | self-hosted connection server, no third-party infrastructure |
| Miro | Excalidraw | whiteboard in the browser, can be embedded in Nextcloud |
The table hides what sits between the lines, so here it is in plain words: Matrix is the most powerful chat system on the list and at the same time the most demanding to operate. A twenty-person team almost always does better with Nextcloud Talk or Mattermost and misses nothing. And with video calls, be sceptical of your own enthusiasm: internal calls and meetings with guests work well with Talk or Jitsi — if you run hundred-participant webinars daily, test exactly that before you believe it.
The calculation that actually works out
“Open source is free” is the sentence these projects fail on. The licence costs nothing — servers, updates, backups, monitoring and the hour someone spends wiring up single sign-on cost money or time. Few projects fail on the software; many fail on operations.
The honest comparison is therefore: subscription costs of all replaced tools versus operating costs of your own instances. Replace five SaaS subscriptions with one server running all five alternatives and you almost always come out ahead. Build your own infrastructure for a single tool and you almost never do. In between lies the grey zone where a managed setup pays off: with selfhosting as a service, the tools run on infrastructure in the EU and someone else takes over updates, backups and monitoring — us, for example.
Where to start?
Not with everything at once. The proven entry point is the tool with the biggest pain. Often that’s the wiki, because company knowledge shouldn’t live in a cancellable subscription — sometimes the chat, because every internal message at a US provider is an unnecessary dependency. Migrate one tool, run it in daily use for two months, only then take the next. And if you want to think the office stack through while you’re tidying up: the roadmap for Microsoft 365 is here.
Wondering which of your SaaS subscriptions can be replaced — and which are better off where they are? Get in touch — you’ll get an honest assessment with a sensible order, not ideology.