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).