Peter MacDonald (computer programmer) the Linux Kernel into Dynamically Loadable Modules"). MacDonald co-developed early features of the Linux kernel in the early 1990s, including shared libraries, pseudo terminals, the select call and virtual consoles. He announced Softlanding Linux System (SLS), the first standalone Linux install, for testing in August 1992 (on 15 floppy disks), and for general release in October 1992 (recommending at least 10 MB of disk space). SLS became popular, but also drew criticism. MacDonald was criticized for trying to make money on free software, but defended by Linus Torvalds. Two of the early Linux distributions were made specifically in reaction to
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