Edit: bear in mind that I'm not asking for which license, I'm asking whether it's fair or not.
I want to use the treepedia_dl_public library as a core part of a new website. I checked the repository and noticed that the developers hadn't chosen a license, even though it has been already 2 years since the last time they made a commit.
For the last 2 weeks, I've tried to contact the developers and they didn't answer.
Is it legal to fork an unlicensed project for non-commercial purposes?