\section{A Web and Parallel RDBMS Based Information 
System for Internet Collaboration}

\subsection{Motivation of an Integrated Internet Collaboration System}
In the pre-WWW era, Internet has invented several
systems and tools for information distribution and sharing, including
FTP, Gopher, WAIS and ARCHIE. They were developed to satisfy particular
yet basic needs of sharing information among distributed hosts over
wide area networks. For example, FTP is used to transfer bulk files between
two machines; Gopher and WAIS for authering and publishing plain text files,
and ARCHIE for locating files on various FTP hosts. With alomost the
same motivation and goal for information distribution and sharing,
WWW has integrated all the data transfer protocols in its environment 
so that the WWW browser becomes a universal client program that can access to 
information space served on these particular servers and
new HTTPD servers coexist with them to form
global WWW information space. The WWW browser has been replaced old browsers
used to access these non-HTTPD servers which has being dramatically reduced since the
advent of HTTPD server.

On the other hand, for many years the Internet community has supported
the distribution of bulletins, information and data in a timely fashion
by using two popular collaboation methods: mailing list and USENET news system.

A mailing list is a group of email addresses that can all be reached
by sending messages to a single address. Mail sent to that address is redistributed
to all subscribers. The list of addressees are usually maintained with an automated mailing
list management program, such as Majordomo, LISTSERV and ListProc. This program also
handles the other aspects of list maintainance, such as remote reconfiguration, 
archival and remote retrieval of messages, digests.
One major advantage of mailing list is the email-based news delivery that prompts the immediate
or delay attention to a subscriber, since the notification of mail arrival is active and
is close to the email system that is familar to most desktop users. The drawback of
the data replication and mail transport propragation approach adopted in mailing list method
is the overhead of inefficient use of network bandwidth, CPU resource and signicifant
amounts of disk storage at each subscriber's host. Distributed maintenance cost is also a
problem.

The mail delivery in mailing list system relies on the basic Internet email services provided
over wide area networks, such as the Simple Mail Transfer Protocol (SMTP) \cite{smtp} for host-to-host
mail transfer over TCP, Post Office Protocol (POP-3) \cite{pop3} for user-to-mailbox access, and
Sendmail \cite{sendmail} program for the implementation of mail delivery. Built upon the
Internet email services are various mail reader and handle programs such as MH, XMH, Emacs, pine
to read and manage mailboxes on the desktop machine.

The USENET news system is invented to reduce the amount of resources used in mailing list method.
Articles are now stored in one central repository on a receiving host instead of 
in each subscriber's mailbox. Using the client-server model and the NNTP \cite{nntp}
protocol to retrieve articels on the NNTP server from a client program, the USENET news
system has evolved to handle central storage, indexing, retrieval, and distribution of
news. USENET news is an efficient means of providing news and bulletin
service to subscribers on UNIX and other hosts worldwide. 

NNTP specifies a protocol for the distribution, inquiry, retrieval, and posting of
news articles using a reliable stream (such as TCP) client-server model. NNTP
is designed so that news articles need only be stored on one central host, and subscribers on
other hosts attached to the network may read news using stream connections
to the news host. For news distribution, USENET news system uses a new 
propagation and duplicaiton mechanism \cite{rfc850}
to reduce the overhead of network bandwidth congestion on a single centralized news server,
by caching recently arrived and retrieved news articles on a hiarachical intermediate news
servers to serve and mediate regional or local requests. A new article is usually first
posted on a local news server. That machine then forwards it to all its neighbor news servers that
are interested in the newsgroup of the message. The sites receiving the incoming article
accept it locally and then in turn forward the article to all their interest neighbors. This
process continues until the entire network has seen the article. To read articles in a newsgroup,
a user usually connects to the local news server using the client program of particular news reader
such as rn,tn,nn,xrn.

The unit items of information handled by the mailing list and USENET news system
are collectively referred as 'news'. Such news
provides for the rapid dissemination of text-based items of interest such as software bug fixes,
new product reviews, technical tips. News usually are stored one piece per file and
each consists of a series of heading text, which contain the sender's identification
and organizational affiliation, timestamps, email reply paths, subject,
newsgroup (subject category), and other attributes as defined in \cite{rfc822}.

While mailing list and USENET news system are 
different in the distribution mechanism, they
all use asynchronized message passing for text-oriented 
collaboration which is not real-time.
Internet has invented another collaborative protocol called 
Internet Relay Chat (IRC) \cite{irc}
that uses real-time synchronized message passing for text-based 
teleconferencing over the wide area networks.
IRC uses again the client-server model in which a single chat 
server forms a central
point for clients to connect to, performing the required message 
delivery/multiplexing and other
functions. IRC messages are always lines of characters terminated 
with a CR-LF pair.

The mailing list, USENET news and IRC are developed for particular needs
of Internet collaboration, with their particular protocols and set of tools.
Table \ref{comparison} outlines their comparison in various aspects.



\end{enumerate}

\subsection{System Configuration}

\subsection{Newsgroup and Mailing List Archive}

\subsection{Chat and Bulletin Board}

\subsection{Conclusion}
