Cisco IOS

The Internetworking Operating System, known as IOS, is a family of proprietary network operating systems used on router and network switch models made by Cisco Systems, packaging routing, switching, internetworking, and telecommunications functions into a single multitasking operating system. Although its code base includes a cooperative multitasking kernel, most IOS features have since been ported to other kernels such as Linux and QNX for use across Cisco products. Not every Cisco networking product runs IOS: some Catalyst switches run IOS XE, Cisco ASR routers run either IOS XE or IOS XR, and the Nexus and MDS switches Cisco makes for data center environments run the Linux based Cisco NX-OS instead. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/