.xcassets

Asset Catalog

Handled by macOS itself

Format facts

MIME type: application/x-xcassets
Apple UTI: com.apple.xcassets
Stock Quick Look: macOS renders a preview
Planned approach (census): native-sufficient
Icon hint: generic-icon
Prevalence: universal

Renderer note (from the census)

Finder previews the bundle as a folder

Gotchas: directory bundle