GNU Project some is released under a weak copyleft or a lax, push-over free software license. The first goal of the GNU project was to create a whole free-software operating system. By 1992, the GNU project had completed all of the major operating system utilities, but had not completed their proposed operating system kernel, GNU Hurd. With the release of the Linux kernel, started independently by Linus Torvalds in 1991, and released under the GPL with version 0.12 in 1992, for the first time it was possible to run an operating system composed completely of free software. Though the Linux kernel is
Kernel (operating system) in 1984, bundled with its Macintosh personal computer. Apple moved to a nanokernel design in Mac OS 8.6. Against this, the modern macOS (originally named Mac OS X) is based on Darwin, which uses a hybrid kernel called XNU, which was created by combining the 4.3BSD kernel and the Mach kernel. Microsoft Windows was first released in 1985 as an add-on to MS-DOS. Because of its dependence on another operating system, initial releases of Windows, prior to Windows 95, were considered an operating environment (not to be confused with an operating system). This product line continued to evolve through the