Among the most useful are Archive Utility, now including Apple Archive compression, and Storage Management. But Network Utility is now non-functional.
Sometimes you don’t know of a silent update until an app misbehaves or crashes. One day, the innocent-looking plist tucked away in a LaunchAgents folder could be malicious.
My screenshots are now tagged with metadata supporting Spotlight search, and Hazel uses that to sort them into folders automatically.
A quick tour through Folder Actions (AppleScript), Hazel (System Preferences pane, commercial), and fswatch and their potential uses.
Running shell scripts from Swift playgrounds is easy, but there’s more work needed to support droplets and folder actions.
Folder actions can do many useful things. Here I develop one to decompress Zip archives.