great look, decent code.

examples at https://penrose.cs.cmu.edu/try/?examples each example has three tabs:

    .substance => data
    .style => low level 2d vector art
    .domain => data ranges

heavy lifting done by .style, random fragment:

    forall repeatable Element a; Element b; Element c
    where IsProduct( a, b, c )
    {
       shape productShape = Rectangle {
          center: ( b.u, c.v )
          width: a.width - global.boxPadding
          height: a.height - global.boxPadding
          cornerRadius: 2.0
          fillColor: a.boxColor
       }

       shape productText = Equation {
          string: a.label
          center: productShape.center
          fontSize: "8px"
          fillColor: a.labelColor
       }
    }