Modified by Intel Andrew S. Tanenbaum; Note added later: Some people have pointed out online that if MINIX had a GPL license, Intel might not have used it since then it would have had to publish the modifications to the code. Maybe yes, maybe no, but the modifications were no doubt technical issues involving which mode processes run in, etc. My understanding, however, is that the small size and modular microkernel structure were the primary attractions. Many people (including me) don't like the idea of an all-powerful management engine in there at all (since it is a possible security hole and a dangerous idea in the first place), but that is Intel's business decision and a separate issue from the code it runs. A company as big as Intel could obviously write its own OS if it had to. My point is that big companies with lots of resources and expertise sometimes use microkernels, especially in embedded systems. The L4 microkernel has been running inside smartphone chips for years. I certainly hope Intel did ...