As Matthew said, we still use it for some of our studies and it works well. The only thing I can add is that the Simile timeline does allow to have the time bands working on different but connected scales, which for instance allows one band to have days and another band to have months, and they stay synched as you scroll. Visually this is very appealing and data-wise you could see the benefit if you had a lot of events in a short time span. We've never implemented that functionality, but it's worth mentioning. http://www.simile-widgets.org/timeline/ shows a demo timeline with different time scales for different bands.