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
Disk operating system to be installed inside the computer. Some disk operating systems were the operating system for the entire computer system. Disk operating system A disk operating system (abbreviated DOS) is a computer operating system that can use a disk storage device, such as a floppy disk, hard disk drive, or optical disc. A disk operating system must provide a file system for organizing, reading, and writing files on the storage disk. Strictly speaking, this definition does not apply to current generations of operating systems, such as versions of Microsoft Windows in use, and is more appropriately used only for older generations