curs_overlay(3x) on macOS
The text db99eba313a8, as macOS 13.5, macOS 13.4, macOS 13.3, macOS 13.2, macOS 13.1, macOS 13.0, macOS 12.5, macOS 12.4, macOS 12.3, macOS 12.2, macOS 12.1, macOS 12.0.1 shipped it.
overlay and manipulate overlapped curses windows