Open Core License
Functional Source License (FSL-1.1-MIT)
Free for 99.9% of developers: build commercial apps, internal tools, SaaS platforms, and mobile apps without paying a dime.
PERMITTED USE
Build Commercial Products
You can embed ULTSQL directly into commercial mobile apps, desktop software, internal enterprise microservices, and consumer SaaS platforms without royalty or license fees.
THE ONLY RESTRICTION
No Managed Database Hosting
The only prohibited activity is offering ULTSQL as a commercial managed database hosting service (e.g. AWS RDS or Supabase alternative) that directly competes with ULTSQL offerings.
CONVERSION TIMELINE
Automatic 2-Year MIT Conversion
On the second anniversary of each release date, that version's license automatically converts to the standard, unconditional MIT license forever.
Can I use ULTSQL in a closed-source commercial Flutter or Dart app?
Yes, absolutely. You are 100% permitted to ship ULTSQL inside your commercial proprietary iOS, Android, macOS, Windows, Linux, and Web applications without open-sourcing your code or paying any licensing fees.
Can I use ULTSQL as the backend database for my SaaS business?
Yes. As long as your SaaS product's primary value is not reselling managed ULTSQL hosting (e.g., an automated DBaaS platform), your use is completely permitted under FSL-1.1-MIT.
Why does ULTSQL use FSL instead of AGPL or BSL?
FSL (created by Sentry) is designed to be developer-friendly. Unlike AGPL, it does not force you to open source your proprietary app. Unlike BSL, it has a strict 2-year conversion clause into pure MIT.
Who holds the copyright to ULTSQL?
ULTSQL is created and copyrighted by Om Patel and community contributors.