Ancient history: Tanenbaum vs Torvalds

The Minix 1 source code was available on floppy disks, and in the appendix to Andrew S. Tanenbaum's 1987 book OperatingSystems: DesignandImplementation. Soon a Usenet group grew around Minix with 40,000 subscribers, including Linus Torvalds who added new features. However, he grew frustrated with Tanenbaum's unwillingness to let Minix grow away from its tight educational focus, so in 1991, Torvalds announced on “I'm doing a (free) operating system (just a hobby, won't be big and professional like GNU.” When Torvalds was later accused in a book of stealing Minix code, Tanenbaum defended him, but rather waspishly said: "Linus didn’t sit down in a vacuum and suddenly type in the Linux source code. He had my book, was running Minix, and undoubtedly knew the history (since it’s in my book). But the code was his. The proof of this is that he messed the design up."

The Tanenbaum–Torvalds debate, revisited in the appendix to the 1999 book OpenSources: VoicesfromtheOpenSourceRevolution was a

thread over two weeks early in 1992, over the merits of monolithic kernels and microkernels – starting with a Tanenbaum contribution best summed up as ‘monolithic kernels are obsolete.’ It trailed off inconclusively, but after a few years many claimed ‘Linus won’, simply because of Linux's market share. The debate continues, but you can find Tanenbaum's more recent thoughts on the matter at