Key to a successful application of functional electrical stimulation as a rehabilitation therapy (also termed functional electrical therapy or FET) is modular, portable, programmable, and versatile transcutaneous electrical stimulation technology. In this article a hardware platform, Compex Motion, that has been used successfully to develop numerous FET systems for walking, reaching and grasping is presented. The Compex Motion stimulator can be programmed to generate any arbitrary stimulation sequence, which can be controlled or regulated using any external sensor or sensory system. The stimulator has four current regulated stimulation channels that can be expanded to multiples of four channels (8,16,20,...). The stimulation sequences are stored on readily exchangeable memory chip-card. By replacing the chip-card the function of the stimulator is changed instantaneously to provide another function or FET treatment. The Compex Motion system was used as a FET device with more than 60 acute and chronic stroke and spinal cord injured (SCI) patients.