ProjectLibre is an open source, freely available project management software system intended ultimately as a standalone replacement for Microsoft Project.
Bugzilla is a web-based general-purpose bugtracker and testing tool originally developed and used by the Mozilla project, and licensed under the Mozilla Public License.
TaskJuggler is GPL-licensed (free software) project management software that runs under the Linux and Unix operating systems and is programmed in C++ using the Qt toolkit and KDE libraries.
XMind is a mind mapping and brainstorming software, developed by XMind Ltd.
Redmine is a free and open source, web-based project management and issue tracking tool.
Tiki Wiki CMS Groupware
Tiki Wiki CMS Groupware or simply Tiki, originally known as TikiWiki, is a free and open source Wiki-based content management system and online office suite written primarily in PHP and distributed under the GNU Lesser General Public License (LGPL) license.
Mantis Bug Tracker
Mantis Bug Tracker is a free and open source, web-based bug tracking system.
GanttProject is GPL-licensed (free software) Java based, project management software that runs under the Windows, Linux and Mac OS X operating systems.
Savane is a free web-based software hosting system.
GNATS is the GNU project's issue-tracking software.
web2project is a web-based, multi-user, multi-language Project Management application.
OpenProj is an open source project management software application.
Tryton is a three-tier high-level general purpose computer application platform on top of which is built an Enterprise resource planning (ERP) business solution through a set of Tryton modules.
Calligra Plan (formerly KPlato) is a project management application that can create Gantt-style charts and is part of Calligra Suite – formerly included with KOffice.
Feng Office Community Edition
Feng Office Community Edition (formerly OpenGoo) is an open source collaboration platform developed and supported by Feng Office and the OpenGoo community.
OpenProject is a web-based project management system for location-independent team collaboration.
The Bug Genie
The Bug Genie is free and open source, web-based project management and bug tracking system.
Celtx (/ˈkɛltᵻks/) is media pre-production software, designed for creating and organizing media projects like screenplays, films, videos, stageplays, audio plays, documentaries, machinima, comics, games and podcasts.
Phabricator is a suite of web-based software development collaboration tools, includingthe Differential code review tool,the Diffusion repository browser, the Herald change monitoring tool,the Maniphest bug tracker andthe Phriction wiki.
Originally "GitLab" referred to a free repository manager.
Endeavour Software Project Management
Endeavour Software Project Management is an open-source solution to manage large-scale enterprise software projects in an iterative and incremental development process.
LibrePlan is a free software web application for project management, developed by the Fundación para o Fomento da Calidade Industrial e Desenvolvemento Tecnolóxico de Galicia, dependent of the Ministry of Industry of the Xunta de Galicia.
Apache Allura is an open-source forge software for managing source code repositories, bug reports, discussions, wiki pages, blogs and more for any number of individual projects.
Project.net is an open source, enterprise scale project management application for Microsoft Windows and Unix operating systems.
Apache Bloodhound is an open source web-based project management and bug tracking system.
Open Workbench is a free project management software focused on scheduling.
Kallithea is a cross-platform free software source code management system, the primary goal of which is to provide a repository hosting service with features for collaboration, such as forking, pull requests, code review, issue tracking etc.
Roundup (issue tracker)
Roundup is an open-source issue or bug tracking system featuring a command-line, web and e-mail interface.
Tuleap (project management)
Tuleap is a project management system for managing application lifecycles, Agile development and design projects, V-model, Requirement Management, IT Services Management, and so on.
dotProject is a web-based, multi-user, multi-language project management application.
Agilo for Trac
Agilo for Trac (formally known as Agilo for Scrum) is an open source, web-based Scrum tool to support the agile Scrum software development process.
FusionForge is a free software application descendant of the forge (web-based project-management and collaboration software) originally created for running the SourceForge.
Kune is a free/open source distributed social network focused on collaboration rather than just on communication.
GForge is a free software fork of the web-based project-management and collaboration software originally created for SourceForge, called Savane.
Collabtive is a web-based project management software published as free software.