A good test of how good the 'vfs' support is in Tcl 8.4a4 (with the vfs package) is to take some code that we not designed with a vfs in mind and see if it still works.
The Tkhtml package comes with a script 'hv.tcl' which can be used as a local .html browser. We can test whether it works with remote files over a vfs:
set site "http://www.scriptics.com" package require vfs; vfs::urltype::Mount http; set argc 1; set site [list $file]; source hv.tcl
and, after a couple of second's delay, we actually get the page, and we can browse the web...