Linux has a long and stormy relationship [1] with another Unix-like operating system known as Minix [2]. Noted author and computer scientist Andrew S. Tanenbaum released the first version of Minix in 1987 as a tool for teaching students about operating systems, and this small and well-documented system soon became popular with OS enthusiasts. In a post to the Minix newsgroup, upstart Finnish undergraduate Linus Torvalds announced his own experimental system in 1991, and many early Linux contributors came from the ranks of the Minix community.

But Tanenbaum and Torvalds clashed early over issues of design. Tanenbaum has always favored the microkernel architecture, a distinguishing feature of Minix to this day (see the box titled "Why Can't Computers Just Work All the Time?"). Linus, on the other hand, built Linux with a monolithic kernel, with filesystems, drivers, and other components incorporated into the kernel. In a famous post to the Minix group, the Minix creator referred to Linux as "… a giant step back to the 1970s," and a confident reply from young Torvalds to this leading expert in the field of operating systems is early evidence of his now-legendary directness. Still, Linus has acknowledged the importance of Tanenbaum's work to the formation of his own ideas. In his autobiography Just for Fun [3], Linus refers to Tanenbaum's Operating Systems: Design and Implementation as the book that changed his life.

The debate about micro- versus monolithic kernels goes on to this day, and just as Linux didn't fade away, neither did Minix. Version 3 of the Minix operating system is designed with the objective of creating a system that is more secure and reliable than comparable POSIX systems, and a BSD-style open source license makes the latest Minix a strong candidate for production as well as educational uses. Minix is even attracting the attention of some major sponsors. The EU is now sponsoring the project with several million Euros of funding, and Google has a number of Minix projects in its "Summer of Code" program.

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