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
   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

Proiektor  
   A flexible and extensible groupware and project management solution, Apache license.
   http://www.bluedynamics.org/products/Proiektor

GATMAN  
   Provides network/user management and group collaboration via Java client and web. Written in java/jsp/xml. Bootstrapped from real sysadmin work in Hamburg, Germany.
   http://www.gatman.de/

XenIntranet  
   A modular intranet/extranet solution based on the Ampoliros PHP web applications platform and taking advantage of Ampoliros features. GNU license.
   http://www.xenintranet.com/

Civitas Digitalis  
   A PHP & MySQL-based application serving as the technical fundament of a fully customizable user-driven online community.
   http://trivini.com/civitas/

Hipergate  
   Web-based open source groupware written in Java/JSP with support for PostgreSQL, Oracle and SQL Server.
   http://www.hipergate.org/

JResearch.org  
   JGossip is a forum implemented on J2EE platform using Struts framework. The project supports all the main features.
   http://www.jresearch.org/

Lucane  
   Lucane is a free groupware platform written in Java, designed with extensibilty in mind.
   http://lucane.org/

Oekaki Open Source Poteto  
   PHP/MySQL program which allows the user to create a database-driven, account-based, web art board/community. The project is working to convert Oekaki Poteto (OP) into a developer-friendly package.
   http://www.suteki.nu/oekakios/

GroupSuite  
   A planned PHP-based groupware including calendar, address book, forum, ticket system, WebMail, CRM and DMS.
   http://sourceforge.net/projects/groupsuite/

DOE2000 Electronic Notebook  
   Modular, extensible, notebook framework to make cross-platform interoperating prototype implementations. Allows shared input and display of sketches, text, equations, images, graphs, other data types. Tools for authentication, other services.
   http://www.csm.ornl.gov/enote/