Underrepresentation in computing is a global problem, marked by a disturbing lack of access to computing resources and education among people underrepresented by race, ethnicity, gender, income, disability, and sexual-orientation status. It is urgent that we address this divide between those with and without the knowledge to create computational artifacts or even basic functional literacy. Important alliances for broadening participation (BP) are catalyzing efforts to engage more people in computing, but they are not enough. We need solid research as well.