The difficulty  is in the authentication.  The WWW server only  has an IP
address. It  needs to know the  person's e-mail address, the  name of the
list, and somehow it has to verify  that this person is an owner. Then it
must acquire the information, present it to the user, and so on. Building
a PUT request  and sending it to  LISTSERV is not difficult at  all. In a
dedicated interface, the information  necessary for authentication can be
saved in a configuration file, and the interface could keep a list of the
lists you manage. With a WWW interface  it would have to be retyped every
time.
 
  Eric