Linux is a free and open-source operating system that was inspired by the design of Unix. It is widely used for servers, desktops, and mobile devices, known for its stability, security, and flexibility. Some of the most popular Linux distributions are:
Debian, Fedora, CentOS, Ubuntu, OpenSUSE
How to Find Out Distribution of Linux You Are Running
There are several BSD systems. All these systems are derived from the original Berkeley Software Distribution (BSD) system, which was developed at the University of California, Berkeley in the 1970s. They all share common codebase and functionality, but they each have different focus, development model, and community.
Here is a short, incomplete list: FreeBSD, OpenBSD, NetBSD
How to Install QEMU guest agent on FreeBSD