A shell script that takes a dd'ed image from a RasPi install and shrinks it down as far as possible so that it'll fit onto another, smaller microSD card. Used for cloning installs.

Remember, it won't work on a card, only a filesystem rip.

A Linux driver system that allows unprivileged code to implement file systems. Because the file system drivers exist entirely out of kernel space, you can do some pretty crazy things with the file system block layer...

A utility which uses the FUSE functionality of the Linux kernel to implement NFS in such a way that it can spoof user credentials when mounting exported file systems so you can get access to files that you wouldn't be able to otherwise.