Experimental additions have been made to a conventional virtual machine system (VM/370) in order to support a centralized program library management service for a group of interdependent users. These additions enable users to share read/write access to a data base as well as processing services. Although the primary motivation was the enhancement of performance, considerable attention was given to retaining the inherent advantages of the virtual machine system. Extended applications of the basic technique are described and the implications of such extensions on operating system design are considered.