[escherize]

One of the best features of draw.io is embedding the graph information into exported pngs. So if I save a version of a document as a png, and you open it with the Draw.io app, then you can edit the png as if you had opened the project file itself!

I know pico-8 also does this png embedding (where you can export a cart as a png, and others can load the png into their pico-8 machine).

Are there other apps that do this? It's really a cool hack!

[zamadatix]

Spore encoded the creature data in the alpha channel... which always struck me as odd since they managed the site that hosted the images and could guarantee metadata wasn't removed after upload. I think a few other games used metadata to share but the names aren't coming to mind.

[jraph]

LibreOffice can embed the source document when exporting to PDF. They call this feature Hybrid PDF.

[davidjgraph]

draw.io / diagrams.net also embeds the data inside PDF.

[Leo_Verto]

It's possible to export LaTeX to PDF with the latter containing the LaTeX source.

[lol768]

Back in the day I think Macromedia Fireworks used this model as well..