Magma is an experimental Network File System for Linux and BSD kernels. It uses libfuse to interact with the kernel. It's based on Distributed Hash Tables. Every thing (files, directory, devices, FIFO, symlinks) is called a Flare Object which is an opaque box which can be moved across nodes if the network topology changes.
Magma also provides a network balancer, a telnet console to manage nodes, and much more. Its current state is under development. Don't expect something fully working.