A system software component that is external to the operating system kernel. If the phrase is used to refer to the operating system itself, it is redundant because an operating system "is" software.

The National Institute of Standards and Technology's new definition of "critical software" is foundational to new federal efforts to exert more control over the code supply chain. CISA Contracts NIST ...

To help agencies comply with the Biden administration’s cybersecurity executive order, the National Institute of Standards and Technology on June 25 posted a new definition of "critical software" for ...

(1) The system software infrastructure in a cloud computing environment. See cloud operating system and cloud management system. (2) Any application that resides on, and is run from, the Internet or ...