Minix 3

Minix 3 is a small, Unix-like operating system. It is published under a BSD-3-Clause license and is a successor project to the earlier versions, Minix 1 and 2. The project's main goal is for the system to be fault-tolerant by detecting and repairing its faults on the fly, with no user intervention. The main uses of the system are envisaged to be embedded systems and education. Minix 3 supports IA-32 and ARM architecture processors. It can also run on emulators or virtual machines, such as Bochs, VMware Workstation, Microsoft Virtual PC, Oracle VirtualBox, and QEMU. A port to PowerPC architecture is in development. The distribution comes on a live CD and does not support live USB installation. Minix 3 is believed to have inspired the Intel Management Engine (ME) OS found in Intel's Platform Controller Hub, starting with the introduction of ME 11, which is used with Skylake and Kaby Lake processors. It was debated that Minix could have been the most widely used OS on x86/AMD64 processors, with more installations than Microsoft Windows, Linux, or macOS, because of its use in the Intel ME. The project has been dormant since 2018, and the latest release is 3.4.0 rc6 from 2017, although the Minix 3 discussion group is still active. Reflecting on the nature of monolithic kernel based systems, where a driver (which has, according to Minix creator Tanenbaum, approximately 3–7 times as many bugs as a usual program) can bring down the whole system, Minix 3 aims to create an operating system that is a "reliable, self-healing, multiserver Unix clone". To achieve that, the code running in kernel must be minimal, with the file server, process server, and each device driver running as separate user-mode processes. Each driver is carefully monitored by a part of the system named the reincarnation server. If a driver fails to respond to pings from this server, it is shut down and replaced by a fresh copy of the driver. In a monolithic system, a bug in a driver can easily crash the whole kernel. This is far less likely to occur in Minix 3.