Read on for the formal legal stuff. The plain text version is:

FireShed is free to use for Brigades. If you are government department (not a brigade) or a commercial organisation, a seperate license will be negotiated. Copyright remains wth Steve Davis.

End-User License for FireShed software

Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

https://creativecommons.org/licenses/by-nc-nd/4.0/