Because of the speed at which neural signals change, experimental perturbations benefit from precise temporal and spatial control. This control is best instantiated in closed-loop systems, where neural signals directly influence the timing and character of interventions such as multi-electrode stimulation. Commercial systems are lacking for closed-loop use with multi-electrode arrays in freely moving animals. The NeuroRighter system fills this gap by offering a multi-electrode recording system capable of complex closed-loop stimulation to all electrodes. Thanks to advances in open-source software development, circuit design, and hardware fabrication, other users can replicate the system or re-engineer it to better tackle problems in neuroscience and neuroengineering, in vitro and in vivo. These will form the basis of future therapies that take advantage of stimulation from multiple microelectrodes. Electrical training of neural tissue with patterned closed-loop stimulation (Jackson et al., 2006; Bakkum et al., 2008) has the potential to aid recovery from stroke or trauma, and to provide restoration or enhancement of cognitive function (Berger and Glanzman, 2005).