CollabNet's Issue Tracker is a variant of BugZilla, but a more generalized tool for tracking different kinds of activities.
Issue Tracker classifies issues into several types:
Each project that uses Issue Tracker has its own issues database. For public projects, all registered users may query, view, and report issues. Proprietary projects limit access to project members.
Project members have additional permissions within Issue Tracker to modify and reassign issues, as well as generate reports. Project members are also notified automatically by email whenever issues are assigned to them or there is activity on issues affecting their work.