* If you're interested in a minimum-coding solution, forms
and CGI-bin scripts are a pretty good hack. HTTP authentication
isn't that hard -- ask Tony Sanders <firstname.lastname@example.org>, and he can probably
point you toward the relavent perl code.
* If you're interested in a scalable solution, have a look
at USENET news! The only trick is to enhance browsers
to understand the message/rfc822 content type a little better,
(including message/rfc822 bodies whose bodies are text/html)
and to support NNTP posting and thread navigation.
Conventional newsreaders are bad because they keep a connection to the
NNTP server open during your whole section. But I'm sure they could be
modified to use the gopher/http connect-doit-disconnect style. But
you could have public NNTP servers that zap connections after they
go idle after a few seconds. Then folks with conventional newsreaders
would get the hint that they're not welcome.
You can use the USENET newsgroup hierarchy or make up your own.
You don't have to expire old articles.