Minix 3/The history of Minix 3

It is best to think of Minix 3 as an new operating system (OS) based on an earlier educational OS, known as Minix.

Minix 1 & 2
Minix 1 was written by Andrew S Tannenbaum to to provide examples for his textbook "Operating Systems: Design and Implementation". This was necessary because. beginning with Unix version 7, Bell Labs had begun to refuse permission to use Unix sources for teaching.

The text of the book contained an abridged version of the source The source and binaries were also available on floppy disk.

A revised version: Minix 2 was released in 1997, with the second edition of the book, now co-authored with Albert Woodhull. Minix version 2.0 was now POSIX compliant. Minix 1 & 2 were not only designed to illustrate principles of OS Design and Implementation they were also examples of a Microkernel architecture.

Minix 3
While Minix 1 and 2 were operating systems designed for teaching, Minix 3 was also aimed as a product in the Embedded software market. Its release under the BSD-3-Clause license was intended to open it up to commercial use.

The key feature of the Minixes is their Microkernel architecture. Minix 3 had been further developed by adding a fault tolerant architeccture. Minix 3 was also developed as a usable desktop operating system on which Minix 3 could be compiled and developed. The software and utilities available was expanded greatly by  importing the netBSD userland software. By version 3.2.0, much of the Minix userland software (ie. software is not part of the kernel and executed in user mode) had been replaced by the equivalent from the netBSD.

This convergence with netBSD had several good reasons, the principal one being that the chief value of the Minix OS is in its Microkernel architecture and its adaptations for high reliability. Maintaining and supporting the Minix utilities would no longer divert effort from kernel development. NetBSD is very compliant with the relevant standards and the code is well written with a focus on portability. The netBSD license allows it to be incorporated into commercial products with little fear of commercially difficult obligations.

In addition to netBSD userland software, Minix 3.4.0 has adopted the pkgsrc package management system making thousands of packages available to the user.

An early form of Minix 3 was notably used in the Intel Management Engine firmware version 11 used in many PC motherboards.