The Google filesystem
A userspace filesystem which stores data in a MySQL database
Filesystem in Userspace is an interface for filesystems implemented in userspace.
FUR is a application that let the user mount a Windows CE based device on your Linux file system.
A dynamic software updating system for multi-threaded userspace applications that applies immediate updates using stack reconstruction
An userspace (fuse) filesystem that implements private storage for pseudo persistent processes.
pcmciautils is a suite of userspace tools for PCMCIA support in the Linux 2.6 kernel.
fuse_adfs is a module for FUSE to present the contents of ADFS floppy disc images as a mountable filesystem on Linux.