Neurofeedback is a subtype of biofeedback in which the neurophysiological information associated with mental states is presented to the individual in order to teach them to modulate those same states. Neurofeedback is a non-invasive strategy with clinical potential for the treatment of psychiatric symptoms and disorders. Despite being promising, the diverse protocol variations present a challenge for the study of their effects and applications. Thus, the objective of this project is the development of a neurofeedback system using fNIRS in the prefrontal region. We used open source software, Unity and OpenViBe, so that the resulting system can be made publicly available at the end of this project, and it is expected to thereby, help to create a basis for the development of a robust and reproducible affective neurofeedback protocol. The choice of the prefrontal region occurs both because it is an area with little interference in the fNIRS technique, and because it is closely related to affection and various psychiatric disorders.