Near-threshold computing (NTC) has emerged as a promising approach to achieving an order of magnitude improvement in energy efficiency of microprocessors. The key feature of NTC is to lower the supply voltage of chips to a value only slightly higher than the threshold voltage. NTC lowers power consumption by an order of magnitude or more. The reduction in power however comes with associated costs and challenges that include low operating frequency, less reliable operation of both logic and memory and much higher sensitivity to parameter variability. Industry is actively investigating the technology and has produced prototypes that show promising initial results. However, many challenges remain before NTC can become mainstream.