One of our main design goals is to try to construct a
mostly clutter-free interface, i.e. largely devoid of
widgets and other UI artefacts, but without compromising essential functionality. Depending on the breadth
and nature of said functionality this is more or less
achievable ([11] is a good example showing how this
can be accomplished for equation writing). For instance, colour selection is hardly possible without a
helper tool such as a palette. Another challenge is to
fulfil the requirement of producing digital quality documents using close-to-natural pen interaction, that is, to
be as near to a pen on paper experience as possible,
but with resulting documents properly formatted and
professional-looking. This discrepancy is especially difficult to bridge for text input, as trying to smoothly convert handwritten text into a coherent and meaningful
ASCII rendition is not trivial. We explain how we address those various challenges further below.