Citadel is an advanced messaging and collaboration system for groupware and BBS applications. Users can connect to Citadel using any telnet, WWW, or client software. Among the features supported are public and private message bases (rooms), electronic mail, real-time chat, paging, shared calendaring, address books, mailing lists, and more. Unlike other collaboration servers, Citadel provides its own data stores and is therefore extremely easy to install; you don't have to "bring your own" email and database because they're built in. The server is multithreaded and scalable. In addition, SMTP, IMAP, and POP3 servers are built-in for easy connection to Internet mail. Citadel is both robust and mature; it has been in production since 1987.
alph implements and analyzes historical and traditional ciphers and codes, such as polyalphabetic, substitutional, and mixed employing human-reconstructable algorithms. It provides a pipe filter interface in order to encrypt and decrypt block text to achieve transparency. The program is meant to be used in conjunction with external programs that transfer data, resulting in transparent encryption or decryption of information. The program can thus be used as a mail filter, IRC filter, IM filter, and so on.
WebCit is a Web-based, AJAX-enabled frontend to the Citadel groupware/collaboration system. It is an attractive Web middleware layer that allows user-friendly access. By combining WebCit and Citadel, you can have a versatile online environment with many users concurrently accessing the same system using the user interface of their choice (text, Web, or downloaded client software).
nms is a set of drop-in replacements for the CGI scripts found at Matt's Script Archive. They have been developed from the ground up to emulate their behavior, but in many cases are better written and more secure. The collection includes form mail, guest book, simple search, and counter scripts.
DBOX is a free communication package for ISPs. It supports a large number of message formats such as RFC/UUCP, ZConnect, Janus/Janus2, Alphabox, and GSbox. It is designed for large installations and includes a WWW package with an email/HTML gateway, an HTML online shop, support for POP3/IMAP4, and personal homepages with HTTP/FTP upload.