BCI2000 is a general-purpose system for brain-computer interface (BCI) research. It can also be used for data acquisition, stimulus presentation, and brain monitoring applications. The mission of the BCI2000 project is to facilitate research and applications in the areas described above. Our vision is that BCI2000 will become a widely used software tool for diverse areas of real-time biosignal processing. BCI2000 system is available for free for non-profit research and educational purposes. It has been provided to about 600 laboratories around the world.