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. The BCI2000 system is available for free for non-profit research and educational purposes. It has been provided to more than 240 laboratories around the world. More information about BCI2000, including instructions for getting access to the source code, is available on http://www.bci2000.org/.