%% This is part of the OpTeX project, see http://petr.olsak.net/optex

\_famdecl [KP Fonts] \Kpfonts {KP fonts -- Johannes Kepler project}
        {\sans \mono \light \caps \swash} {\rm \bf \it \bi} {KpMath}
        {[KpRoman-Regular]}
        {\_def\_fontnamegen {[Kp\_subfamV-\_currV]:\_capsV\_swaV\_fontfeatures}}

\_wlog{\_detokenize{%
Modifiers:^^J
 \sans ...... sans serif^^J
 \mono ...... non-proportional^^J
 \light ..... light (\rm, \it) + semibold (\bf, \bi) variants^^J
 \caps ...... caps & small caps^^J
 \swash ..... alternative Q letter^^J
}}

\_def\_RBIfvars{\_fvars Regular Bold Italic BoldItalic }
\_moddef \resetmod {\_fsetV subfam=Roman,caps={},swa={} \_RBIfvars }
\_moddef \sans     {\_fsetV subfam=Sans \_RBIfvars }
\_moddef \mono     {\_fsetV subfam=Mono \_RBIfvars }
\_moddef \light    {\_fsetV subfam=Roman \_fvars Light Semibold LightItalic SemiboldItalic }
\_moddef \caps     {\_fsetV caps=+smcp;\_ffonum; }
\_moddef \nocaps   {\_fsetV caps={} }
\_moddef \swash    {\_fsetV swa=+swsh; }
\_moddef \noswash  {\_fsetV swa={} }

\_initfontfamily % new font family must be initialized

\_loadmath {[KpMath-Regular]}
\_loadboldmath {[KpMath-Bold]} \to {[KpMath-Regular]}

\_endcode

The KP fonts family includes more variants of Math fonts.
Only Regular / Bold pair is loaded as default.

There are alternatives:

\doloadmath \loadmath {KpMath-Light}
\loadboldmath {[KpMath-Semibold]} \to {[KpMath-Light]}

or

\doloadmath \loadmath {KpMath-Sans}