The main goal of the EyeHarp project is to allow people with paralysis resulting from Amyotrophic Lateral Sclerosis to play music using only their eyes. To build this, I was inspired by the EyeWriter open source initiative: "...a low-cost eye-tracking apparatus & custom software that allows graffiti writers and artists with paralysis resulting from Amyotrophic lateral sclerosis to draw using only their eyes". Alternatively, the instrument can be controlled using the mouse pointer (MouseHarp version). Then the free software camera mouse (http://www.cameramouse.org/) can be used to control the instrument with head movements. Any technology that can take control of the mouse pointer can be used in order to control the instrument. That way the MouseHarp could be an appropriate instrument for many cases of people with physical disabilities. The MouseHarp version is completely independent from the EyeWriter project. Combining the MouseHarp source with the source of the EyeWriter project, we get the EyeHarp! A low-cost gaze controlled musical instrument! Both versions are free and open source. By Zacharias Vamvakousis. A free and open source project. More info: http://theeyeharp.blogspot.com/