Request Tracker - issue tracking system in CGI and Perl

•    Perl

Request Tracker is an enterprise-grade issue tracking system which thousands of organizations use for bug tracking, help desk ticketing, customer service, workflow processes, change management etc. This product is very stable and been around for over 10 years.

Eventum - issue tracking system

•    PHP

Eventum is a user-friendly and flexible issue tracking system that can be used by a support department to track incoming technical support requests, or by a software development team to quickly organize tasks and bugs.

Flyspray - Web-based Bug Tracking System in PHP

•    PHP

Flyspray is a lightweight, web-based bug tracking system written in PHP for assisting with software development and project managements. It supports Multiple projects, File attachments, Advanced search features, Atom/RSS feeds, Voting for tasks, Comments, Roadmaps and lot more.

Bugzilla

•    Perl

Bugzilla is most popular and widely used "Defect Tracking System" or "Bug-Tracking System".

Elastik - issue tracker that can track anything

•    PHP

The open source ticket/issue tracker that can track anything. It supports multiple projects and each project could have flexible fields, categories, status and status workflows. Data could be exported as CSV. Each User can customize their own dashboard.

MantisBT - Bug Tracking System in PHP

•    PHP

MantisBT is a web-based bug tracking system written in the PHP and works with MySQL, MS SQL, and PostgreSQL databases and a webserver. It supports multiple projects in a single instance. Its features set include Full text search, Built in Reports, Custom fields, Change History, RSS Feeds, Export to csv, Excel, Word, Upload attachments, Wiki Integration ,LDAP Integration, SOAP interface, Support for mobile devices, localization support and lot more.

SingleBugs - A simple single person bug tracker

•    Go

Singlebugs is a sole developer focused bug tracking tool. It takes its interface interface cues from Outlook's three panel design where the leftmost are the projects, the middle the issues and the right running commentary. It has a fulltext search bar which searches across all three streams making a very fluid development experience. Since it is designed to work locally it is also very fast.

Squash - Bug Smashing Tool

•    Ruby

Squash is an exception reporting and bug analysis tool from Square. Squash lets you analyze information about a bug to determine its root cause. Squash includes a full-featured commenting system, ticket-management system. Squash analyzes the stack trace of every exception, and determines which line in the backtrace is the source of the bug. It then uses git to figure out who might have caused the bug,

Clockingit - Project Management, Collaboration and Time Tracking in Ruby

•    Ruby

Clockingit / Jobsworth can be used for helpdesk support ticketing, customer liasion, resource management and has a range of CRM type functionality. It helps to Plan your projects, see your schedule, know if you’re slipping behind and why. Time Tracking and extensive reports help you show your clients exactly what you’ve done and for how long. It supports flexible reporting, gantt chart & scheduling, accounting/billing system integration and lot more.

JTrac

•    Java

JTrac is an open source and highly customizable issue-tracking web-application written in Java.

jobsworth - Project Management, Collaboration and Time Tracking.

•    Ruby

Welcome to the jobsworth project management, support ticketing and CRM system. This software is licensed under the AGPLv3. Jobsworth can be used for helpdesk support ticketing, customer liasion, resource management (eg. systems and password tracking) and has a range of CRM type functionality. Plan your projects, see your schedule, know if you're slipping behind and why. Time Tracking and extensive reports help you show your clients exactly what you've done and for how long.

The Bug Genie - Issue Tracking and Project Management

•    PHP

The Bug Genie offers powerful Project Management, Wiki, Scrum support, LDAP authentication, Email notifications, and a huge list of features like timeline, roadmaps, attachments, SCM integration, time estimation, customized workflows and lot more.

AdvTicket, New Generation HelpDesk, TicketTracker, BugTracking Solution

AdvTicket Asp.Net Mvc based New Generation Helpdesk, Support Desk, Ticket Tracker, Bug Tracking, Issue Tracking Solution.

Mantisbt - Bug Tracker

•    PHP

MantisBT is an open source issue tracker that provides a delicate balance between simplicity and power. Users are able to get started in minutes and start managing their projects while collaborating with their teammates and clients effectively.

GLPI - Asset Management Software

•    PHP

GLPI is the Information Resource-Manager with an additional Administration- Interface. You can use it to build up a database with an inventory for your company (computer, software, printers...). It has enhanced functions to make the daily life for the administrators easier, like a job-tracking-system with mail-notification and methods to build a database with basic information about your network-topology.

Community Add-on's for Gemini Issue Tracker

Countersoft Gemini Community Add-on's project providing users with additional integrations with Gemini, an ASP.NET Issue Tracker / Bug Tracker / Project Management platform.

SlickTicket

•    ASPNET

A trouble-ticket/help desk solution written by those who are tired of the bloated 'Industry Standard' systems. Designed by along-side many unsatisfied users of available ticketing systems; this is the most user-friendly, advanced ticketing system available.

Bug.Net Defect Tracking Components

Bug.Net server-side controls and components to add defect (bug) tracking to your current ASP.NET website.

Bosco Bug Tracking System

•    PHP

Bosco is a rewrite of the popular Bugzilla defect tracking software in PHP. Among its goals are database-independence and ease of maintenance and modification. An API is also planned to allow external applications to work with Bosco's data.

sBugs Defect Tracking System

•    Java

sBugs is a defect tracking system written in Java, using JSP and PostgreSQL. It aims to be easy to install, maintain, and use. It does not have all the bells and whistles of a system like Bugzilla, but is feature-rich and extendable.