I believe I run MenuetOS once over decade years ago. Now it's 26 years old since its first release. I can only be jealous of such stamina and wish it prosperous years ahead.

Has it had any commercial success?

Interview With Ville Turjanmaa, the Creator of MenuetOS (2001) (1)

Ville Turjanmaa: The current distribution fits to a single floppy and I plan to keep the basic OS functions that way.

— Man of his word!

1. https://www.osnews.com/story/93/interview-with-ville-turjanm...

Note that the 64-bit version is not open source.

KolibriOS (https://kolibrios.org/en) is an active fork of the open source 32-bit version.

I remember stumbling uppon Menuet when it was still 32 bits only, (probably around 2006?). I tried it, booting from an actual floppy disk at the time. Nowadays, I don't even know where I would find a computer that still has a floppy disk drive. Time flies.

A similar project discussed a couple days ago: https://news.ycombinator.com/item?id=46866544