The past few decades have witnessed a rapid explosion in research surrounding robotic exoskeletons due to their promising applications in medicine and human performance augmentation. Several advances in technology have led to the development of more energy efficient and viable prototypes of these devices. However, despite this rapid advancement in exoskeleton technology, most of the developed devices are limited to laboratory testing and a very few of them are commercially available for human use. This chapter discusses the advances in various constituting technologies including actuation, sensing, materials, and controls that made exoskeleton research feasible. Also presented are case studies on two state-of-the-art robotic exoskeletons, Harmony and Maestro, developed for rehabilitation of the upper body. The chapter concludes with a discussion on the ongoing challenges in exoskeleton design and ethical, social, and legal considerations related to the use of these devices and the future of exoskeletons.