phpBB phpBB is an open source, flat style, message board written in PHP. It has all standard message board features. http://www.phpbb.com

Citadel/UX Unix implementation, a BBS method begun in 1981 with a CP/M-based BBS http://uncnsrd.mt-kisco.ny.us/citadel/

TWIG A useful intranet/groupware tool and application framework. Written and implemented with PHP. Goal is to be a simple, cross-platform, fast way to access/share almost any kind of information, GPL license. http://twig.screwdriver.net/

GlobeCom Jukebox A group-enabled audio/jukebox application. BSD-style license. http://www.globecom.se/jukebox/

MetaDot Open Source Portal Server Free Open Source Portal Server allowing point and click community, content and XML syndication management on the Web, email, cellphone, other media. http://www.metadot.com/

phpGroupWare A multi-user web-based groupware suite written in PHP. It also provides an API for developing additional applications. http://www.phpgroupware.org

Nexist Topic Map based java system, "a testbed for developing tools for Web collaboration", Apache license. http://nexist.sourceforge.net

onShore onShore, a consulting firm, has a web-based, multi-user time-billing tool, GPL license. http://www.onshore.com/

GNA - Frontdesk A distributed group e-mail application for software/helpdesk functions, GPL license. http://www.gnacademy.org/uu-gna/tech/dbedit/frontdesk.html

WorldPilot Zope-based program that provides an IMAP based web mail client, contact and address book, notes, ToDo's, calendar and workgroup sharing. http://www.worldpilot.org

PHProjekt Open source groupware with calendar, project management, request tracker and 12 other modules. Supports more than 16 languages. Requires mysql, oracle, postgres or informix db. http://www.PHProjekt.com

JetSpeed [from Apache's Jakarta] A servlet implementation of an open protocol GroupWare product. Backend (search engines, news, weather, POP3/IMAP/LDAP/NNTP, database) is based on other open source packages. http://jakarta.apache.org/jetspeed/

Groupware Summary of open source groupware software. http://www.svpal.org/~grantbow/groupware.html

WEBO - Web based groupware Web based groupware providing group scheduling, addressbooks, shared folders. http://sourceforge.net/projects/weborganizer

Outreach Project Tool GPL PHP groupware package targeted at project development. Manages documents, tasks, requests, basic newsletters, knowledge entries, stores e-mail copies, e-mail repository address. Requires LAMP. http://sourceforge.net/projects/outreach

OpenACS OpenACS (Open Architecture Community System) is an advanced toolkit for building scalable, community-oriented web applications. If you're thinking of building an enterprise-level web application, OpenACS is a solid, proven foundation that will give you a 3-6 month headstart. http://openacs.org

MoreGroupware Moregroupware is a Web-based Groupware written in PHP4. Includes modules like calendar, notes, todo, and contacts. It is database abstracted and uses a template engine for output. http://www.moregroupware.org/

PhpCollab Project management focused, inspired by the now defunct Macromedia Sitespring. http://www.phpcollab.com

Intranet Collaboration Suite WEB-based collaboration server: Mail, Organiser and Documents manager. http://www.intranetsuite.org

Isogest Your Office in a Box A web-based Italian office communication suite for archiving digital documents. Works with Hylafax server. http://isogest.sourceforge.net