General ATM questions and blue-skying are inappropriate and discouraged by the members on the list. The other list is associated with the general problem of IP over large public networks. As with the ATM list above, its purpose is for an IETF working group. The same restrictions apply. Similar to the Frame Relay Forum, the ATM Forum is an open public forum with over 80 contributing and auditing companies.
Membership includes many international companies.
Some companies also participate in ANSI T1S1 and other standards bodies. It is tough to get a number on this. There are a few companies with hardware they can demonstrate. More who have made product announcements. Many more who have stated product intentions.