"A Two-view Document Editor with User-definable Document Structure."
    Kenneth P. Brooks.
    November 1, 1988.  192 pages.

Author's Abstract

    Lilac is an experimental document preparation system which combines
    the best features of batch-style document formatters and WYSIWYG
    editors.  To do this it offers the user two views of the document:
    a WYSIWYG view and a  formatter-like source view.  Changes in
    either view are rapidly propagated to the other.  This report
    describes both the user interface design and the implementation
    mechanisms used to build Lilac.