Strata is free software. You can use it, modify it, and run it on a commercial server — but if you redistribute changes, those changes must also be open-source under the same license.
Strata is licensed under the GNU General Public License v3.0. That means you have broad freedom to use and modify the framework — including on monetised servers — but if you redistribute your modifications (publish a fork, sell a modified copy, hand a binary to a friend) you have to ship the source under the same license.
What this is not: a non-commercial license. You can absolutely use Strata on a server that takes donations or sells priority queue. You just can't take the source private.
© Strata Framework contributors · v1.0.0
This summary is informational and does not replace the full license text. The legally binding terms are in the LICENSE file at the root of the repository, and at gnu.org.