Afuse is an automounting file system implemented in user-space using
FUSE. Afuse currently implements the most basic functionality that can
be expected by an automounter; that is it manages a directory of virtual
directories. If one of these virtual directories is accessed and is not
already automounted, afuse will attempt to mount a filesystem onto that
directory. If the mount succeeds the requested access proceeds as normal,
otherwise it will fail with an error.

The generated package includes the script afuse-avahissh: this will use
avahi to automatically populate the root directory with hosts advertising
their sftp service via Avahi.
As it's not essential for general usage, avahi is considered an optional
dependency (install it if you want to use that script).