[dagmx]

Isn’t Fuse itself LGPL? Thats perhaps one reason since copyleft licenses aren’t favourable from their view.

I would really love any equivalent API though as dealing with Perforce is a pain in the butt sometimes, and what Microsoft have done with the Prrforce Virtual File system is amazing.

[arthur2e5]

Macfuse itself has been closed source for a long time. Whether their EULA is compatible with the LGPL though, I don’t know. (Also, the old question: are APIs copyrightable?)

[dagmx]

But do they bundle libfuse as a dylib? If they do, they’re probably in the right.

And API copyright aside, how would one prove it’s only API compatible and not using the implementation as well without also open sourcing their implementation?

It would almost be better to be similar but not the same. Then everyone else can just do subtle ifdef changes to their fuse code.