Linux kernel kernel and loadable kernel modules (LKMs), unlike in many other kernels and operating systems, is not meant to be very stable by design. The Linux kernel, developed by contributors worldwide, is a prominent example of free and open source software. Day-to-day development discussions take place on the Linux kernel mailing list (LKML). The Linux kernel is released under the GNU General Public License version 2 (GPLv2), with some firmware images released under various non-free licenses. In April 1991, Linus Torvalds, at the time a 21-year-old computer science student at the University of Helsinki, Finland, started working on some simple ideas
Darwin (operating system) in Terminal will show the Darwin version number, and the command uname -v will show the XNU build version string, which includes the Darwin version number. Due to the free software nature of Darwin, there are many projects that aim to modify or enhance the operating system. OpenDarwin was a community-led operating system based on the Darwin system. It was founded in April 2002 by Apple Inc. and Internet Systems Consortium. Its goal was to increase collaboration between Apple developers and the free software community. Apple benefited from the project because improvements to OpenDarwin would be incorporated into Darwin releases;