The creation, deployment and management of network architecture is manual, time consuming and costly. To the network architect the creation process is ad hoc in nature, based on hand crafting small-scale network prototypes that evolve toward wide scale deployment. We envision a different paradigm where `spawning networks' are capable of profiling, spawning, architecting and managing distinct virtual network architectures. This paper provides an overview of the Genesis Kernel framework and its life cycle of spawning virtual networks, and focuses on the design, implementation and evaluation of virtuosity, a plug-in module for the Genesis framework that supports programmable resource management of spawned virtual networks. The design goal of virtuosity is to minimize the complexity of handling multiple spawned virtual networks that potentially operate over multiple resource management timescales. We present a spawning network emulation environment and a virtuosity simulation system. Both of these components are implemented as virtual network extensions to ns. Through simulation we evaluate programmability, signaling, timescales, measurement-based estimation and traffic metering of virtual networks using virtuosity.