Just enough operating system
Just enough operating system (JeOS, pronounced "juice" according to SUSE) is a paradigm for customizing operating systems to fit the needs of a particular application such as for a software appliance. The platform only includes the operating system components required to support a particular application and any other third-party components contained in the appliance (e.g., the kernel).
Source: Wikipedia — Just enough operating system (CC BY-SA 4.0)