Redmine is a web-based free project management and task tracking tool. Redmine offers multiple projects and plugin support; a calendar and a Gantt chart that can be used in visual presentations of projects. Redmine is independent of platform and database.
Developed with the Ruby on Rails web framework. Inspired by Trac's software, which has similar features in the design and development process. As you can install Redmine on your server, you can also use the paid Redmine services, which are customized and easy to use.