Pricing
The engines are free and always will be. The database engine is free for development.
Planned pricing. The database engine is still in development and is not yet published. The tiers below are indicative, may change before launch, and nothing is purchasable today.
Engines
Apache-2.0, forever. Available right now.
- ✓ XQuery 4.0, XSLT 4.0, XPath 4.0
- ✓ Command-line tools
- ✓ No registration, no limits
- ✓ Commercial use permitted
Developer
The whole database engine. Build, deploy and ship.
- ✓ Everything in Engines
- ✓ Build, deploy and ship — including to production
- ✓ Unlimited deployments, never counted
- ✓ No feature gates, no resource limits
- ✓ Free until what you build becomes commercially successful
Business
Once what you built is earning.
- ✓ Everything in Developer
- ✓ Licensed per developer seat
- ✓ No revenue sharing. No royalties. Ever.
- ✓ Email support
- ✓ Building something small? Ask us — we help out.
Distribution
Shipping the engine inside something you distribute.
- ✓ Everything in Business
- ✓ Redistribution and OEM rights
- ✓ Marketplace and embedded products
- ✓ Volume terms, offline activation
What is and isn't free
The engines are free and always will be. XQuery, XSLT, XPath and the CLI tools are Apache-2.0. Use them commercially, redistribute them, embed them — no licence, no registration, no limits. Nothing on this page changes that.
The database engine is free until what you build with it succeeds. Not a crippled trial — the whole engine, no feature gates, no resource caps, unlimited deployments, and you may ship it to production. A licence is needed once the product you built crosses a commercial threshold, or if you redistribute the engine itself inside something you sell.
There is no revenue sharing and there are no royalties. The threshold is a question you answer once, not a cut of your income. Nothing we charge scales with how well you do.
Hobbyists and small teams: tell us what you're building and point us at the repository. We would rather have you using it than not.
Frequently Asked Questions
Are the query engines free?
Yes, always. The XQuery 4.0, XSLT 4.0 and XPath 4.0 engines are open source under Apache-2.0 — no key, no limits, no licence required, commercial use included. Nothing on this page changes that.
Can I use the database engine today?
Not yet. It is still in development and is not published to NuGet. Register and we will let you know when early access opens.
Will the database engine be free?
Free to build with, free to deploy, and free to ship — until the product you built crosses a commercial threshold. Then it moves to per-developer licensing. We are saying this now, before anyone writes a line of code against it, so that nobody has terms changed on them later.
Is the free Developer tier limited in any way?
No. It is the whole engine — no feature gates, no caps on containers, documents or storage, and deployments are unlimited and never counted. The only boundary is commercial success of what you build.
Do you take a percentage of my revenue?
No. There is no revenue sharing and there are no royalties, at any tier. The threshold decides whether you need a licence, not what it costs — above it you buy developer seats at a flat rate, the same as any other component vendor. You will never report revenue to us on an ongoing basis.
How do keys work?
One key per developer. If you lose it, ask and we will issue a replacement — the previous key stops working at that point. Keys never expire on their own, and the engine does not stop working if it cannot reach us.
Can I redistribute the database engine in my product?
That is the Distribution tier — talk to us, including for marketplace listings and embedded or offline products. The query engines are Apache-2.0, so you can redistribute those freely with no agreement at all.
I'm a hobbyist, or an early-stage startup.
Tell us what you are building and point us at the repository. We handle these case by case and we are not looking to squeeze anyone.