[WiseWeasel]

The XML can store references to the binary chunks in standard formats though, alongside the vector shapes and filters.

  <svg viewBox="## ## ## ##">
    <image xlink:href="layer1.png" x="##" y="##" width="##" height="##"/>
    <image xlink:href="layer2.jpg" x="##" y="##" width="##" height="##"/>
    <rect x="##" y="##" width="##" height="##" fill="red"/>
  </svg>

All that's left is to standardize a way to package it.

[arielpts]

Thats actually a good, along with the fake .zip extension.