We are building the XenoServer platform for global computing, a public infrastructure capable of safely hosting untrusted distributed services on behalf of uncooperative paying clients. Service components execute on one or more XenoServers within resource-managed Virtual Machines (VMs) which provide resource isolation, protection, and allow the execution of arbitrary applications and services. To assist the deployment of services on the platform, we provide an effective solution that allows users to fully customize the VMs to be launched by specifying the operating system kernel image and distribution file-system to be used. Moreover, we have implemented mechanisms for facilitating easy and efficient distribution of those kernel and file system images; users build their VMs’ configurations once and use the platform to efficiently launch VMs on large numbers of machines around the world. Initial experiences with our deployment infrastructure demonstrate that the platform provides a practical substrate for public global computing; we show how a complex service running on the user’s own customized Linux environment can be deployed to multiple XenoServers around the world in under 45 seconds.