Linux kernel 4.0.0 Linux is a mostly POSIX-compliant Unix-inspired operating system kernel, originally implemented by Linus Torvalds and now maintained as an international project. It's the base and common namegiver to a wide array of Linux distributions. The kernel provides all modern Unix-y features, like true process multitasking, virtual memory, virtual and clustered filesystem support, complex networking and extensive support for various hardware and machine plattforms.