macOS

Notes

To focus the menu bar (top left), use ⌃f2
To focus the menu bar (top right), use ⌃f8
To focus the Help menu item in the menu bar (and therefore the menu bar itself), use ⌘⇧/. This will let you query all menu items. Useful for when you want to know the keyboard shortcut for an item, or if an item doesn't have a shortcut at all
To paste an image from the clipboard into the filesystem (from the command line), use pngpaste util