Volunteer, disinterested participation in open source communities of innovation is shown to be compatible with the pursuit of professional goals; indeed, the two often go together. Those who contribute to open source software are both conscientious stakeholders in a community and economic 鈥渟leepers鈥? Besides assuming the position of an activist devoted to the 鈥渃ause鈥? amateur developers stake out an occupational position and send signals attesting their participation in the community. Although they define themselves mainly as champions of a 鈥渇ree鈥?model of citizenship, they also subtly infiltrate channels of employment in the labor market so as to build up their professional image and lay claim to upward social mobility.