The Best Linux Distributions Without systemd systemd: A Quick Recap Historically, the startup sequence in a Linux system was a replica of the initialization system that was introduced with System V Unix (SysV). The SysV init system adhered to the Unix philosophy. When people refer to the Unix philosophy, they usually reduce it to the well-known soundbite “Do one thing, and do it well.” And that thing was to start as the first process and then start other processes. It also culled zombies now and then. SysV init did its job well enough, but it didn’t do it too efficiently. It started processes serially, one after the other. There was no parallelism. The design bottle-necked the throughput. This was more or less masked by the speed gains of modern hardware, and it’s not as if booting a Linux computer took an interminable age. But yes, technically, it could have been made more efficient.