I’ve spent some time looking at other timeline software tools, as well as actual visual depictions of timelines on art history, and I’m pleased to note that I haven’t found anyone else who has already implemented my idea.  Here are some of the closest contenders:

Via Sourceforge:

• Timeline: the link goes to the example page.  From their website: “timeline is a script that inputs a source file and transforms it in a graphic timeline in many formats (html, ps, png, etc). Only html is implemented by now.”
• Timeline Creator in Flex 2 (La Ligne du Temps): I can’t offer a description from their website, as it is in French.  Nonetheless from the look of the screenshots this is a fairly advanced program that allows a user to create sophisticated timelines in a standalone program.

These two projects are the closest I could find to my own idea, and both of them are sufficiently different.  The first is probably the closest to what I’m interested in, and with it’s fairly simple source file could easily be converted to read from a database.  It also draws the data in html, which is a good start to putting it online.  Right now, however, it’s very static.  It doesn’t have a method to pull specific information from a database; it doesn’t have a way for the user to configure which timelines to view on the fly; it doesn’t have any kind of AJAX plugin that would return the information requested by the user.

The second looks like a great program, but is a standalone program not running on the web, or with the capacity to serve as a front-end to an archive database.  Still, the designers have obviously thought through a lot of the features they offer, and it’s probably worthwhile to pay attention to their functionality.

Art related:

• Picasso timeline: Non-interactive, hard to read and, dare I say, ugly?
• About Pablo Picasso Timeline: This is a much more organized chronological timeline that is similar to what you might see in the back of a retrospective catalog.  It incorporates some pictures, and even a few links to artwork that appear in a separate window.  This is definitely the sort of idea that I want to capture and improve upon.

This is hardly an exhaustive search of timelines, timeline software, etc.  If you have any that you particularly like, please let me know so I can take a look!