Optical (photonic) computing uses photons for computation. The advantages of this approach are inherent parallelism and high processing speeds. Recent advances in silicon photonics have led to miniaturization of optical computing systems on an integrated chip. Moreover, high energy efficiency of such systems promise to help overcoming the von Neumann bottleneck and open a window for new photonic applications. In this talk we will discuss how optical hardware can impact artificial intelligence, quantum computing, and cryptocurrency.