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
Operating system and Sparc servers, and PCs. Apple's macOS, a replacement for Apple's earlier (non-Unix) Mac OS, is a hybrid kernel-based BSD variant derived from NeXTSTEP, Mach, and FreeBSD. Unix interoperability was sought by establishing the POSIX standard. The POSIX standard can be applied to any operating system, although it was originally created for various Unix variants. A subgroup of the Unix family is the Berkeley Software Distribution family, which includes FreeBSD, NetBSD, and OpenBSD. These operating systems are most commonly found on webservers, although they can also function as a personal computer OS. The Internet owes much of its existence to