The first electronic digital computers were variations on the protean design of a limited Turing machine, which described not a single device but a schema, and which could assume many forms and could develop in many directions. It became what various groups of people made of it. The computer thus has little or no history of its own. Rather, it has histories derived from the histories of the groups of practitioners who saw in it, or in some yet to be envisioned form of it, the potential to realise their agendas and aspirations. What kinds of computers we have designed since 1945, and what kinds of programs we have written for them, reflect not so much the nature of the computer as the purposes and aspirations of the communities who guided those designs and wrote those programs. Their work reflects not the history of the computer but the histories of those groups, even as the use of computers in many cases fundamentally redirected the course of those histories. Separating the histories of computing, or perhaps even of computings, shifts attention to the major communities, or bodies of shared disciplinary practices, who embraced the new device and helped to shape it by adapting it to their needs and aspirations.