This is the project that spawned my CSS mini timeline adventure (which I ended up not using, actually). It’s a really simple proof of concept for analyzing family relationships:
You enter basic information for the family and on the fly it draws a timeline and shows you how old each person was when other major family events happened (siblings born, deaths, etc.). Super simple. It’s mostly so you can get a better feel for what all the dates actually mean — you can see that so-and-so was only 16 when her mother died, or that there’s a gap where a child could have been born, etc.
Also, this is just a proof of concept — I’m not completely satisfied with the design, and the print stylesheet needs more work (but yes, there’s a print stylesheet), and there are plenty of issues left to resolve (some of which are on the GitHub issues page for the project) — but you get the idea.
Something like this would be more useful when hooked up with a data store (like FamilySearch, for example, which wouldn’t be very hard to do). Then you wouldn’t have to type everything in.