Four challenges to building large networked virtual environments (NVEs) are ever-increasing complexity, fidelity, scalability, and portability. We require a powerful, flexible, efficient, portable software infrastructure to overcome these challenges. We examine one such example, software infrastructure, which is currently the basis of dozens of NVE efforts. Its use of modern object-oriented inheritance and its use of an interpreted configuration programming language meet these requirements while achieving the efficiency to support thousands of entities on current-generation hardware.