Ethernet is spreading—enemies might say metastasizing—into applications far beyond its original use as a local network for workstations. This spread is pushed forward by three primary factors: Ethernet’s culture of standardization and interoperability, reduced price of components because of economy of scale, and the rapid evolution of foundational signaling technology that culture makes possible. At the same time, Ethernet is being pulled into new applications by increasing computerization and the absence of robust common interconnect standards (Figure 1). This pull is coming from areas as diverse as automobiles, industrial controls, and cloud computing centers.