Education policy increasingly takes place across borders and sectors, involving a variety of both human and nonhuman actors. This comparative policy paper traces the 'policy mobilities,' 'fast policy' processes and distributed 'policy assemblages' that have led to the introduction of new computer programming practices into schools and curricula in England, Sweden and Australia. Across the three contexts, government advisors and ministers, venture capital firms, think tanks and philanthropic foundations, non-profit organizations and commercial companies alike have promoted computer programming in schools according to a variety of purposes, aspirations, and commitments. This paper maps and traces the evolution of the organizational networks in each country in order to provide a comparative analysis of computing in schools as an exemplar of accelerated, transnationalizing policy mobility. The analysis demonstrates how computing in schools policy has been assembled through considerable effort to create alignments between diverse actors, the production and circulation of material objects, significant cross-border movement of ideas, people and devices, and the creation of strategic partnerships between government centres and commercial vendors. Computing in schools exemplifies how modern education policy and governance is accomplished through sprawling assemblages of actors, events, materials, money and technologies that move across social, governmental and geographical boundaries.