Project Xanadu.
The Xanadu code sponsored by Autodesk went Open Source at the O'Reilly Open Source Convention on 23 August. This may be of interest to those concerned with hypertext structure and related issues. Official Announcement. The code may be found at UDANAX.COM.
www.xanadu.com/   reviews

Markup Languages.
Historically, markup was used to refer to the process of marking manuscript copy for typesetting with directions for use of type fonts and sizes, spacing, indentation, etc. (from the Chicago Manual of Style, the bible of most publishers.)
www.cs.wpi.edu/~kal/elecdoc/EDmarkup.html   reviews