Ligne du temps
Stop the presses! I have one more timeline to look at. I missed this project in my initial round of research but I think it's interesting enough to warrant an entry.
The timeline is being developed for use by local schools in Quebec, Canada by the Service national du RÉCIT de l'univers social. All the documentation is in French but throwing the wiki through Babelfish has revealed a few more details about the project.
Code development is in Actionscript 3 and Flex 2 and the timeline is deployed using Adobe Flash Player 9. I've found a few projects that use the Flash Player to render their timelines but this is the first I've come across that is being developed using the latest RIA development tools.
Once you get past the login process this timeline is a joy to use. The Flash/Flex interface is clean, intuitive and transitions are smooth as silk. This is the closest I've found to what I want to build myself.
Digging into the documentation reveals some since interesting interface taxonomy. The developers make a clear distinction between time-lines, time-ribbons and time-planks: