FUSE won. It's easy, it works, and it has cross-platform support (macos/linux).
9p is not going to replace fuse now, if ever, on these systems. That's not to say that 9p goes away. But it's not worth worrying about whether FUSE will have more users -- it already has and it probably always will. That said, what's the "resource sharing protocol" for fuse? None of those file systems has a common wire protocol AFAICT. Those servers are hooks from kernel to user to "something". FUSE is not for resource sharing, is it? It's for making it easy to write file systems for Linux users. ron