Implementation of an editing process for Content MathML formulas in common
visual style is a real challenge for a software developer who does not really
want the user to have to understand the structure of Content MathML in order to
edit an expression, since it is expected that users are often not that
technically minded. In this paper, we demonstrate how this aim is achieved in
the context of the Formulator project and discuss features of this MathML
editor, which provides a user with a WYSIWYG editing style while authoring
MathML documents with Content or mixed markup.