Mantisbt - Bug Tracker

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.

It has long list of feature which includes support for multiple projects, Full Text Search, Email notifications, RSS Feeds, Time Tracking, Wiki integration, Multiple ways of Authentication, Multi-DBMS Support and lot more.