* Linux: The most common operating system where you'll find `top`.
* macOS: While technically a Unix-based system, macOS has its own Task Manager interface. You can still use `top` in the Terminal, but it's not the primary way of managing tasks.
* BSD variants: Operating systems like FreeBSD, NetBSD, and OpenBSD also use `top`.
* Solaris: Another Unix-based operating system that includes `top`.
Important to Note: Windows uses its own task manager called "Task Manager" which is a graphical interface. While you can access similar information using command-line tools in Windows, `top` is not available there.