 The need for self-support and community support helped lead to the creation of a strong S/360-67 and CP/CMS user communities, precursors to the open source movement.In the summer of 1970, the CP/CMS team had begun work on a System/370 version of CP/CMS; this would become VM/370.CP-370 proved vital to the S/370 project, by providing a usable simulation of a S/370 on S/360-67 hardware – a reprise of CSC's earlier hardware simulation strategies.