Peter Binkley, in a comment to this blog last week, mentioned the Historical Event Markup and Linking Project (HEML). HEML is the product of Bruce Robertson and several others to provide a basic set of text mark-up and transformations for historical information. A sample timeline, created is HEML is one of Russia under Stalin. The timeline links to underlying documents, and can be displayed in multiple languages and calendars. The site says that the timelines and maps look best when viewed with SVG by Adobe.
Bruce Robertson wrote a brief (and non technical) article on it here.
A search of the Internet on HEML shows that it is mentioned frequently (however you really judge that now-a-days). It has attracted interest.
If you know of live (real) projects that are using HEML, please post a comment. This seems to be a cool tool, so it would be nice to see it in action with real project. (It is unclear if any of the "demos" on the HEML web site are real projects or not.)