"World-wide dissemination of information on the Internet has
evolved through three different stages. It began with the textual
stage (involving protocols like gopher), was followed by explosive
growth during the graphical stage (with HTML/HTTP), and is now
entering the semantic stage (with XML). The evolution of the Web in
some ways parallels the evolution of the user interface (UI)
between humans and computers. The early UIs for mainframe computers
were textual and command-line oriented. This was followed by the
graphical UI (GUI), which helped promote rapid growth in the use of
personal computers. If one were to stretch this Web and UI analogy
further, the next stage in the evolution of the UI should be ...
the semantic UI!"
"Like the semantic web, a semantic UI should clearly separate
the functions of the UI from its visual appearance. Superficial
forms of this separation already exist, in the form of themes and
skins for GUIs, but we are talking about a more radical form of
separation here, where the complete visual structure of the UI may
be altered. The XML framework is a natural choice for achieving
this separation. We can use XML to represent the semantics of the
UI, and use styling mechanisms to control its visual appearance.
For example, a semantic UI may have both a textual and a graphical
representation, with style sheets allowing the user to switch
between the two. Such an approach could help address accessibility
issues, and also facilitate alternative UI technologies such as
"The open source browser platform, Mozilla, provides a nice test
bed for experimenting with semantic UIs. The Mozilla browser itself
clearly separates the browser functionality from the visual UI,
allowing vendors other than Netscape to easily provide their own
GUIs for the browser engine. Mozilla can display both HTML and
XML documents, using Cascading Style Sheets (CSS). It also provides
UI description languages like XUL (XML-based UI Language). In this
article we describe a prototype semantic UI called XMLterm,
implemented using the Mozilla platform."