1)   Census Bug Tracking and Defect Tracking 6.0
Census is a Web-based bug tracking and defect tracking tool that is fully customizable and integrated with VSS. Features include e-mail notifications, user/group/field-level security, role-based workflow, built-in reporting, and revision history.

 2)   Bug Registry 4.1.1
Bug Registry is a bug's hunter for your bugs. Bug Registry is ideal for software development teams, help desk staff, quality assurance engineers, and anyone who needs to know the status of your software's error reports and feature requests.

 3)   Bug Tracker Deluxe 2.5
Bug tracking software for Windows: database management system with ready to use bug-tracking database solutions.

 4)   yKAP Issue Management / Bug Tracking Software 2.00
Powerful, cost effective, Customizable, Web based(XML) Bug / Defect tracking, Issue Management product. Unlimited projects, test environments, attachments, export to PDF/RTF/XLS/HTML/Text, email alerts, exhaustive data/trends analysis, history.