Assembla is the leading provider for SVN and Perforce hosting and has task management features built into it’s platform so software development teams can manage their entire software project in one tool.
IssueBurner provides issue tracking system integrated help desk software. Free hosted web based issue tracker and help desk for customer support applications.
Issue tracking system designed for professional teams
Some organizations seem to try to use an issue tracking system more like a demerit system. One benefit of a comprehensive issue tracking system is having data
BUGtrack - web-based bug tracking and project management
Flyspray, a Bug Tracking System written in PHP.