[SOLAR_FIELDS]

> Nulis is an open source tree editor for writers, inspired by Gingko. To learn how it works, visit https://nulis.io/about and try it out.

He does say "inspired by", though not sure if that was the credit you are expecting.

[nxsynonym]

I think that's plenty of recognition. Most people wouldn't even bother out of fear of losing potential users to the "original".

Unfortunately, being the first or most common product in a space has the side effect of attracting copies, spin offs, or other imitations.