We are exposed to physical and virtual systems every day. They consist of computers, PDAs, wireless devices and increasingly, robots. Each provides services to individual or groups of users whether they are local or remote to the system. Services offered by these systems may be useful beyond these users to others, however connecting many of these systems to more users presents a challenging problem. The primary goal of the research presented in this paper is to demonstrate a scalable approach for connecting multiple users to the services provided by multiple systems. Such an approach must be simple, robust and general to contend with the heterogeneous capabilities of the services. An infrastructure is presented that addresses these scalability requirements and establishes the foundation for contending with heterogeneous services. Additionally, it allows services to be linked to form higher-level abstractions. The infrastructure is demonstrated in simulation on several similar multi-robot systems with multiple users. The results propose it as a solution for large-scale human-system interaction.