In 2001, the Defense Advanced Research Projects Agency called for the creation of commercially viable computing systems that would not only perform at very high levels but also be highly productive. The forthcoming POWER7®-IH system known as Productive, Easy-to-use, Reliable Computing System (PERCS) was IBM's response to this challenge. Compared with state-of-the-art high-performance computing systems in existence today, PERCS has very high performance and productivity goals and achieves them through tight integration of computing, networking, storage, and software. This paper describes the PERCS hardware and software, along with many of the design decisions that went into its creation.