I just came across this

cool hack

The idea isn’t to get Squeak to serve out the file system, but to have a
way to use the FTP protocol as an interface to any data you want, in the
same way that dynamic web servers let you use HTTP for applications far
beyond serving static HTML files.

The article illustrates the challenge by creating a dynamic FTP server that
exposes the internals of a Smalltalk application.  Of course, it would be
equally interesting to expose a Java application this way and browse the
packages, classes and methods.  You could also imagine creating a file
system (/dev/java ?) that would let you create an object with touch
and remove it with rm… 

Completely useless, but totally cool :-)