Minix: Minix was developed by Andrew Tanenbaum and released in 1987. Its name stands for mini-UNIX, with the goal of looking and working like UNIX, but being small enough so that one could understand how it works.

Subsequently, the IEEE organization published a standard for UNIX systems called POSIX. Minix has since evolved toward the new standard.

Linux: Linus Torvalds got a copy of Minix, installed it and made modifications to suit his needs.

Eventually, after writing device drivers and a file system, he had the basis for the kernel of what was to become Linux.

The Linux development emphasized performance and its internal design is monolithic and not at all like that of Minix.

Minix development has recently placed emphasis on building a reliability, and its structure remains much more transparent.