Mantis Bug Tracker is a free and open source, web-based bug tracking system. The most common use of MantisBT is to track software defects.
License: Open Source
Redmine is a more comprehensive project management tool that integrates issue tracking with Agile methodologies, making it ideal for complex projects. In contrast, Mantis Bug Tracker is simpler and faster, focusing primarily on issue tracking, making it better suited for smaller projects or teams.