Tracking the deviations is vital process in any projects. Development, Testing, Networking, DBA, Technical Architects, and so on; everybody need to track defects/deviations in order to monitor the progress and coverage.
In this article, I have listed out the top 10 open source defect tracking tools which will help to your project. The below order is not based on any score cards or rankings.
Table of Contents
Top 10 Open Source Defect Tracking Systems
Bugzilla
Bugzilla is one of the popular bug-tracking system or defect-tracking system. It helps developers to track the defects/bugs. Bugzilla has more features compared to any other open source bug-tracking systems.
Popular social networking site Facebook uses Bugzilla; NASA, Yahoo!, The New York Times, Nokia are some of the fortune companies that uses Bugzilla extensively. Free software projects such as Mozilla, Apache, Gnome, Linux, Open Office, Eclipse, KDE uses Bugzilla system.
Website          :          http://www.bugzilla.org
Latest version :          Bugzilla 4.5.2 and 4.4.2
Flyspray
Flyspray is an easy, web based defect tracking system which helps developers. It is one of the popular bug-tracking systems, next to Bugzilla. PHP.net uses Flyspray. You can see the full list here.
It supports multiple databases: MySQL and PGSQL. It is very easy to install and use. You can have multiple projects; advance search will enhances your productivity; CSS themes; RSS feeds; Road maps; Comments etc.
Website          :          http://flyspray.org/
Latest version :          0.9.9.2.7
JIRA
JIRA is a proprietary issue-tracking system; it is free for use by charities, non-for-profit organizations, open-source projects etc. (except religious orgs). It is developed by Atlassian Inc. JIRA is developed in Java. It supports SOAP, XML-RPC, and REST.
Apache Foundation uses JIRA and Bugzilla. JBoss, Hibernate, Spring Framework, Microsoft Skype, Twitter, LinkedIn, CISCO, BMW are few of the popular clientele of JIRA for bug-tracking and project management.
Website          :          https://www.atlassian.com/software/jira
Latest version :          6.1.7
Mantis
Mantis is free, open-source, web-based, bug-tracking system which is developed in PHP and runs on Windows, Linux, Mac OS X on the server side. It is compatible with all popular browsers. It is very easy to start and use. Email notifications, Access Control, customization are some of the features of Mantis.
It has MantisTouch add-on which allow users to access their system from mobile devices such as iPhone, Android, and Windows mobile.
Website          :          http://www.mantisbt.org
Latest version :          1.2.16
Trac
Trac is a wiki and issue-tracking system which provides an interface to Subversion and Git. It allows wiki markups in issues, and commits. It displays timeline, and roadmap for better tracking and planning respectively. Trac is developed using Python.
You can view the list of users here.
Website          :          http://trac.edgewall.org/
Latest version :          1.0.1
Redmine
Redmine is built on Ruby on Rails framework; it is cross-platform, and cross-database. Redmine supports multiple projects, Gantt chart, Email notifications, Forums, Comments, News, Multiple LDAP authentication, Multilanguage etc. You can see the demo here. You can see list of who uses Redmine here.
Website          :          http://www.redmine.org
Latest version :          2.4.3
Request Tracker
Request Tracker is an issue-tracking system which is built using Perl. RT can also be used as help desk ticketing, business workflow, network operations, etc. It comes with mobile compatibility, dashboards, theme editor, rich text editing, charts, etc.
Check here about who uses Request Tracker.
Website          :          http://www.bestpractical.com/rt
Latest version :          4.2
EventNum
EventNum is a flexible issue tracking system which is developed by MySQL team. It features email integration, SCM integration, Project Management, etc.
Website          :          http://dev.mysql.com/downloads/other/eventum/features.html
Latest version :          2.2
OTRS
OTRS is an open source help desk software and management tool licensed under AGPL where you can download, install, and edit at free of cost. It has new dashboard, access and permission management, and it supports retina display.
Website          :          http://www.otrs.com
Latest version :          3.3
Fossil
Fossil is developed in C language, and uses SQLite as its database. It is robust, reliable, CGI/SGGI enabled, AutoSync mode which reduces the forking/merging, simple interface and many more. It runs on Windows, Linux, OpenBSD, Mac OS,
Website          :          http://www.fossil-scm.org
Latest version :          1.28