Why the License Actually Matters Here
Two projects can both call themselves "open source" and behave completely differently once you try to self-host, modify, or build a commercial product on top of them. The license text is what determines this — not the marketing page. For infrastructure software specifically (databases, observability platforms, message queues), the license terms affect whether a cloud provider can resell your project as a hosted service without contributing back, and whether your own modifications need to be shared.
Disclaimer: this is a general, educational overview, not legal advice — consult counsel for decisions specific to your situation.
MIT License
MIT is about as permissive as licenses get: you can use, modify, and redistribute the code, including in closed-source or commercial products, with essentially no obligations beyond keeping the original copyright notice. This makes it popular for libraries and tools meant to be embedded widely, but it also means a cloud provider could take an MIT-licensed project, host it as a paid service, and never contribute a line back — which is exactly the scenario that led some infrastructure projects to move away from it.
AGPLv3
The Affero GPL (AGPLv3) closes the specific gap MIT leaves open: if you modify AGPLv3-licensed software and run it as a network service (even without distributing the binary), you're required to make your modified source available to users of that service. This is the "network use is distribution" clause that distinguishes AGPL from regular GPL. In practice, this means you're free to self-host, modify, and use AGPLv3 software commercially — the obligation only triggers if you modify it and offer it as a service to others without sharing those changes.
SSPL (Server Side Public License)
SSPL was created by MongoDB specifically to go further than AGPL: it requires that if you offer the licensed software as a service, you must also open source the entire stack you used to run that service — not just your modifications to the software itself. This is significantly more restrictive, and the Open Source Initiative doesn't recognize SSPL as an OSI-approved open source license, because it effectively targets a specific business model (competing cloud providers) rather than being a general license anyone can build on freely.
What This Means Practically for Self-Hosting
Self-hosting internally? All three are fine.
MIT, AGPLv3, and SSPL all permit running the software for your own internal use without triggering any obligation to share code back.
Building a product on top? Check what "modify" means for you.
If you fork and modify AGPLv3 or SSPL code to offer as your own service, you take on source disclosure obligations that MIT wouldn't require — worth reviewing before committing engineering time to deep customization.
Worried about future relicensing?
Permissive licenses like MIT can't be revoked for code already released, but a project's future versions can switch license terms — something to watch on any dependency you build critical infrastructure around.
Conclusion
The right license for your use case depends on what you're trying to protect — permissive licenses optimize for adoption, copyleft licenses like AGPLv3 optimize for keeping improvements in the community, and licenses like SSPL optimize for protecting a project from being resold wholesale by larger competitors. None of these are "more open source" than the others in a moral sense — they're different tools solving different problems, and understanding which one applies before you build on a dependency saves headaches later.
Frequently Asked Questions
Can I self-host AGPLv3 software commercially?
Yes. AGPLv3 permits self-hosting and commercial internal use freely. The source-disclosure obligation only triggers if you modify the software and offer that modified version as a network service to other users without sharing your changes.
What's the main difference between AGPLv3 and MIT?
MIT has essentially no obligations beyond preserving the copyright notice, even for closed-source or commercial redistribution. AGPLv3 adds a requirement: if you modify the code and run it as a network service, you must make your modified source available to that service's users. MIT has no such requirement.
Why isn't SSPL considered open source by the Open Source Initiative?
SSPL requires that anyone offering the software as a service also open source the entire surrounding service stack, not just their modifications to the software itself. The OSI doesn't recognize it as OSI-approved because this obligation targets a specific business model rather than being a general-purpose license condition.
Does using AGPLv3 software internally trigger any disclosure obligation?
No. Running AGPLv3 software purely for your own internal use, even at a commercial company, doesn't trigger the source-disclosure clause. The obligation only applies when you modify the software and offer it as a service to external users.
Free Under AGPLv3, No Strings for Self-Hosting
XplurData is AGPLv3-licensed — use it, fork it, self-host it, build on it.
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