I found this a few days ago when I was researching SVG in Flutter. After the initial "why not SVG?" reaction, this is not that bad! As the README says, It is a format for efficient presentation, not an authoring format. You're supposed to author in SVG etc and then export to IVG.
However, SVG Native [1] seems to be very similar, and it's also a subset of SVG, and non-binary.
However, SVG Native [1] seems to be very similar, and it's also a subset of SVG, and non-binary.
1: https://svgwg.org/specs/svg-native/