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.
NASLite is a Network Attached Storage (NAS) server operating system designed to transform a basic computer into a dedicated file server. Utilizing highly optimized versions of Samba, uCLibc, BusyBox, and various other Linux tools, it provides SMB/CIFS, FTP, or NFS filesystem support. It accommodates multiple client OSes: Windows, Mac OS X, and Linux. NASLite offers SMART disk monitoring and large file support, and is incredibly easy to install and administer.
Oliver (formerly "WebShare") is a PHP-based FTP front-end, released under the GPL. It allows people to access files normally only available via FTP, effectively providing users with a complete Web-based file management system that, if SSL is enabled on the Web server, uses a single secure connection. This makes it far simpler to use through a firewall. At present, Oliver has only been tested with ProFTPd and PureFTPd but it should work with many others.
RDVz is a Web application for setting conveniences for meeting appointments between several persons. RDVz uses a poll system: each invited user votes for one of the dates suggested by the meeting organizer. The poll organizer chooses possible dates, creates the poll, and sends the poll's URL to the participants. The organizer can export poll results in a CSV file. Anonymous access, MySQL, LDAP, and SSO (CAS) authentication methods are available.
TaskFreak! is a Web-based task manager and todo list. It lets you organize tasks per project, priority, and deadline and context. It is easy to install and to use, and particular attention has been paid to the design and usability in order to improve the productivity by not spending too much time on the tool itself. It is compatible with PHP 4 and 5 and supports both mySQL and SQLite.