In this chapter, we provide an overview of computing circuits in which the spin degree of freedom is utilized, even though the device components are interconnected using more conventional electrical interconnections. A wide variety of computing models can be realized using spin-based building blocks; however, our focus will be on collective-state computing, where mutually interacting, dynamic magnetic systems carry the information and perform the computation. Most of these systems are based on spin-torque oscillators (STOs), where the rich dynamics of STOs perform the computation.