Zwiki's issue tracker is a simple, usable tracker which can be enabled in any zwiki. Issues are just specially-named wiki pages with some extra issue properties, like this one: #1 a test issue. You don't need to remember the exact url or name; just #1 or http://zwiki.org/1 will do.
Here's the default issue tracker view for the issues in this wiki. And the tweaked, editable version we prefer for this site. Also the (default) filter issues view , for slicing and dicing, and the (tweaked) issue browser view , for getting the big picture by issue category.
Why does this work well ?
It leverages the power and simplicity of wiki and email. It is designed to make basic issue tracking as easy as possible and stay out of the way; it has some philosophy in common with Fogbugz . Issue pages can be created via web form, by mail, or by renaming an existing wiki page. They benefit from the usual zwiki functions like recent changes listing, wiki linking, page rating, history, custom DTML queries and so on. You can create, monitor and reply to issues by email. Issues and regular wiki pages may coexist in the same wiki if desired.
Good news, setup is easy
Install Zope & Zwiki, open the zope management interface, Add ZWiki, visit FrontPage/setupTracker. Or just visit /setupTracker in any zwiki (this is safe and reversible, existing content is not affected). See HowToSetUpAZwikiTracker for more detail. You can customize severities, categories, statuses, colours etc. through the web.
This was originally an experiment in Zwiki DTML scripting, with user interface inspired by Peter Bengtsson's early IssueTrackerProduct . The issue tracker views can optionally be installed as editable wiki pages, as on this site, which allows any user with appropriate permissions to make UI and functionality improvements immediately and cheaply through the web. Most issue trackers can't do this. :)