How Mac applications evolved from a multitude of resources to a bundle formed from a standard layout of directories, and how they have come to be largely self-contained in macOS 26.
bundles
The differences between bundles and packages, the differences between app and framework bundles. What you can find inside them, and where to look.
From the resource forks of Classic apps, to versioned and new-style bundles in 2001, document packages, then the incorporation of signatures and notarization tickets.
How to give apps, folders and files custom icons, and how that still uses resource forks, just as it did back in 1984.
ResEdit changed what was in the resource fork. With Mac OS X, Apple moved away from forks to extended attributes, now used for quarantine flags and more.
The Finder is happy to create aliases to most files and folders, provided they aren’t immediately inside a bundle or package. Then it gets all fussy. But why?
Users need to know what changes in each update to macOS, as it may fix existing bugs and introduce new ones. Here’s how I work out what has changed, and its limitations.
Discovering what has been updated in a macOS update isn’t easy. In the case of command tools, it’s just impossible.
Version numbers are simple, aren’t they? So how come so few of Apple’s own apps conform to its own rules? And as for copyright info, forget it, as so many Apple apps seem to.
The differences between a full Gatekeeper check, an AMFI check for integrity, and a normal app open, and why signature errors can be tolerated.
The Eclectic Light Company 