Researching file formats 38: AppleDouble Resource Fork

This blog post is part of a series on file formats research. See this introduction post for more information.

Update: The official format definition is now online here: AppleDouble Resource Fork. Comments welcome directly to the Library of Congress.


Also known as “Dot underscore” files because that’s what they look like, ._likeThis.

Are they related to .DS_Store files? Like, in a concrete way? What about MacBinary? Those are some the questions I went through in my head while working on the FDD (now available above).

macOS makes them. I don’t even want to talk about them. Can I think of something else to talk about, instead? I want my brain to be empty.

beachy waves