They do! A non-commercial license is free, and have a very liberal interpretation of this:
> A purpose is considered non-commercial only if the SOFTWARE is exclusively used to actively work on open-source projects, for learning or teaching on a public academic institution, in the spare time to manage projects where you don't get financial compensation for (hobby usage), by public charitable organizations primarily targeting philanthropy, health research, education or social well-being.
Do they have a free personal version?