The origins of the Linux operating system, by Lars Wirzenius

3 March 2025

A 2023 article about the early days of the Linux operating system, written by Lars Wirzenius, who worked with Linus Torvalds, in the early 1990’s to develop the Linux kernel:

After finishing the game, Linus started learning Intel assembly language. One day he showed me a program that did multitasking. One task or thread would write a stream of the letter “A” on the screen, the other “B”; the context switches were visually obvious when the stream of As became Bs. This was the first version of what would later become known as the Linux kernel.

A kernel is an integral component of an operating system, which has complete control over everything in the system.