Groupware

https://webcollab.sourceforge.io/

https://info.tiki.org/tiki-index.php

Tiki CMS/Groupware, also known as TikiWiki, is a powerful web-based Groupware and Content Management System (CMS), using the PHPexternal link, ADOdb external link and smart external link.

https://www.egroupware.org/en/community/

https://dotproject.net/

dotProject is a volunteer supported Project Management application. There is no "company" behind this project, it is managed, maintained, developed and supported by a volunteer group and by the users themselves.

http://www.collabtive.o-dyn.de/

Collabtive is web-based project management software. Collabtive is intended for small to medium-sized businesses and freelancers.