Alexis de Tocqueville Institution it called "hybrid" source models, in which true open source code is mixed with proprietary code, with the result that intellectual property rights are nullified. To illustrate potential problems with this approach, the book cited the case of Linus Torvalds, creator of Linux. It claimed Torvalds used source code taken from Minix, a small Unix-like operating system used in teaching computer science, to create Linux 0.01, on the theory that no mere student could write an entire Unix-like kernel single-handedly — although writing a kernel of similar size and capabilities is a standard part of many computer science degrees. These
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