This is a great idea. I remember wanting to have VFS support for some applications before, but didn't fully investigate what the CPAN modules out there can do. I just want to point out that it might be worth looking at Tcl's VFS implementation that they have as a core part of the language meaning it can be used at the C level and at the Tcl level. Another thing to look at is the Glib VFS library, but obviously Glib is not going to be available easily everywhere.