The programming language developed for building system software is C. Created in the early 1970s, C has become foundational in programming due to its efficiency and low-level capabilities. It allows for direct manipulation of hardware, making it ideal for operating systems, compilers, and embedded systems. Its syntax and structure have influenced various modern languages, establishing C as a critical component in software development. Moreover, due to its performance, C is well-suited for resource-constrained environments where speed and memory efficiency are paramount.