A minimal operating system is one that has been stripped of all unnecessary components and provides only the functionality needed for a specific purpose. This is particularly useful for mobile computing devices like smartphones, netbooks and tablets, which typically have limited memory and slower processors than the more robust, full-sized PCs. A minimal OS is also useful in virtualization environments where a trimmed-down OS can be used in a hypervisor to save time in deployment and configuration. And makers of embedded systems rely on a minimal OS to help them build only the required functionality into their products.
SUSE Linux Enterprise Just Enough Operating System (JeOS) is an example of a minimal operating system. It is a version of SUSE Linux Enterprise Server that has been trimmed down to about 300 MB, providing a minimal system that is ready to customize to fit specific needs. It was designed for use in virtualization environments such as VMware, Hyper-V, KVM and Xen, and is used to create virtual images for demos, testing, and production purposes.