Linux is a clone of the Unix operating system, developed by Linus Torvalds in the early '90s. It is a multiuser, multitasking operating system that runs on a wide variety of platforms. The Linux kernel has a monolithic architecture for performance reasons. This means that it is self-contained in one binary, and all its services run in kernel space. This was one of the most controversial topics at the beginning. Andy Tanenbaum (professor at the Vrije Universiteit, Amsterdam) argued against its monolithic system, saying: This is a giant step back into the 1970s. He also argued against its portability, saying: LINUX is tied fairly closely to the 80 x 86. Not the way to go. In the minix user group, there still is the thread of full chat involving Torvalds, Tanenbaum, and others.
The following diagram shows the main Linux building...