Summary

This chapter traces the evolution of software from programmable hardware foundations to a dominant force in modern computing systems. Early advances in hardware programmability—through configuration, programmable logic (e.g., FPGAs), and stored-program processors—enabled a separation between physical implementation and functional behavior. The introduction of stable computer architectures (notably IBM System/360) and operating systems created enduring abstractions that allowed software portability, scalability, and rapid innovation. Over time, networking and open-source ecosystems further accelerated the growth of information technology, establishing software as the central driver of capability across computing platforms.

As software methods entered cyber-physical systems (CPS)—including ground, airborne, marine, and space domains—they followed a distinct trajectory shaped by real-time constraints, safety requirements, and physical interaction. Initially introduced to enhance control and diagnostics, software evolved into the core coordinating layer for sensing, decision-making, and actuation, enabling autonomy. This transition was supported by the emergence of real-time operating systems (RTOSes), middleware, and layered software architectures that ensured deterministic behavior and modularity. Across all domains, systems evolved from isolated, hardware-centric designs to distributed, software-intensive platforms, with increasing reliance on standardized frameworks and communication protocols.

The chapter further highlights how software has transformed product development, supply chains, and validation practices. Cyber-physical systems are increasingly influenced by the faster-moving IT ecosystem, adopting open-source components, layered stacks, and continuous update models (e.g., software-defined vehicles). At the same time, safety standards (e.g., ISO 26262, DO-178C) and rigorous verification methods—such as hardware/software co-simulation (MIL, SIL, HIL)—have evolved to address the risks of software-driven behavior. Modern software supply chains are complex, incorporating third-party and open-source dependencies, requiring strong configuration management, traceability, and cybersecurity practices. Overall, the chapter emphasizes a fundamental shift: engineered systems are no longer hardware products with embedded software, but increasingly software platforms embodied in hardware.

Assessment: