Javascript Timeline Visualisation

I am planning to collect some data on the execution of requests within a Java Tomcat container. Each request is fulfilled by data retreived by multiple threads and I want to display this execution wit开发者_如何转开发h a graphic similar to the Google App Engine App Stats tool:

Can anyone suggest a javascript library for drawing this kind of chart? I'm not even sure what the proper name would be for this. Searching for timelines turns up things like http://timeglider.com/jquery/ which seems to do something different.

It looks like a simple timeline with overlapping bars like in a bullet chart. You can see one example here in Protovis. If you know a bit of javascript, you can program one in D3.js, the successor of Protovis. There is a complete example in the demos that come with the download.