{Mikael Sundqvist}
{Extending OpenType math, making choices}
{In the past year and a half, Hans Hagen and I have been
reviewing the typesetting of mathematics in \ConTeXt\ \acro{LMTX}. This
system primarily utilizes OpenType math fonts, and during our work, we
have encountered inconsistencies both within fonts and across
different~fonts.

Microsoft was the first to introduce OpenType math with Cambria Math in
Office 2007. They have also outlined what comes closest to a standard
for OpenType math, although some details are missing or debatable.
Subsequently, several OpenType math fonts were created by converting and
extending older \TeX{} fonts. These fonts often inherited a more
traditional ``\TeX{}y'' behavior, sometimes differing from the behavior
of Cambria. As a result, achieving consistent and visually appealing
output with different types of OpenType math fonts has been challenging.
Throughout our work, we have had to make choices that, in hindsight,
could or should have been made much earlier.

In this brief talk, we will discuss some of these choices, including
italic corrections, handling of zero dimension glyphs, extensibles,
rules, different kern types, accents (both top and bottom), and font
parameters. Our discussion will be illustrated with visual examples, to
keep it accessible and less technical.}