Wikipedia
Redmine
Redmine is a free and open source, web-based project management and issue tracking tool. It allows users to manage multiple projects and associated subprojects. It features per project wikis and forums, time tracking, and flexible role based access control. It includes a calendar and Gantt charts to aid visual representation of projects and their deadlines. Redmine integrates with various version control systems and includes a repository browser and diff viewer.
The design of Redmine is significantly influenced by Trac, a software package with some similar features.
Redmine is written using the Ruby on Rails framework. It is cross-platform and cross-database and supports 34 languages.