History of free and open-source software like Unix, Torvalds' kernel attracted attention from volunteer programmers. Until this point, the GNU project's lack of a kernel meant that no complete free software operating systems existed. The development of Torvalds' kernel closed that last gap. The combination of the almost-finished GNU operating system and the Linux kernel made the first complete free software operating system. Among Linux distributions, Debian GNU/Linux, begun by Ian Murdock in 1993, is noteworthy for being explicitly committed to the GNU and FSF principles of free software. The Debian developers' principles are expressed in the Debian Social Contract. Since its inception, the Debian project
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