Has your Mac got any old apps and other bundles on it? Have their signing certificates been revoked, or are they perhaps unsigned? Here’s a new app to help you find out.
bundles
One of the Finder’s grand illusions, these are standard documents actually composed of a hierarchy of files and folders. Here are some details of common packages.
Trying to decide whether a selected item is an app bundle turns out to be simple, if you cheat.
There’s more to the Finder’s illusions than plain folders. Here’s an explanation of packages and bundles, and how to use and abuse them.
If you wanted to mess someone’s Mac up, you could go into their system files and change things around when they were out at lunch.
The Eclectic Light Company 