Redmine is a flexible project management web application. Written using Ruby on Rails framework, it is cross-platform and cross-database.
ZenTao is an open source project management tool, supporting Scrum. It integrates product management, project management, bug management and QA management, etc., covering all lifecycle of software development.
Ora is an all-in-one realtime workspace for teams. It has everything your team might need to be productive. Task management, kanban, time tracking, chat, reports on projects and team productivity. It is powerful, yet simple and easy to use.
PlanShell offers professional Redmine (project & tracking management) hosting service secured with automatic backup including agile support well integrated with GIT/SVN and time & issues tracking system with helpdesk and other helpful features.