OnTime 2007 is a bug tracker, issue tracker, task tracker, and help desk ticket tracker that relies heavily on AJAX. OnTime 2007 is currently in beta, and you can get 3 months of their hosted solution free by signing up here. There’s a video that runs through the AJAX front-end and shows how the new web version responds more like a Windows app. I would like to see a video that steps through the major functionality of the application, as video demos are huge in helping people get a high-level understanding of an application.
One thing I like about OnTime is that their previous version, OnTime 2006, comes with a VS.NET client so you can access it without leaving your IDE (assuming you’re a .NET developer). I’ve seen this attempted before, but it looks like the OnTime guys have pulled it off pretty well. I hope they’re thinking of doing the same for the 2007 version, because this is a major selling point for the .NET shops I work with.
OnTime offers a hosted solution, or you can host it in-house. They also include a feature list & comparison with their competitors (including FogBugz).
OnTime offer the product free for single-users, and are currently offering teams limited beta accounts with 3 months of free hosting service. Pricing starts at $495 for 5 users.