Software as a service (SaaS) featuring software for accessing and exploring interactive photorealistic virtual historical and cinematic environments; providing non-downloadable software for generating, streaming, and interacting with computer-generated virtual worlds featuring artificial-intelligence-driven non-player characters; platform as a service (PaaS) featuring computer software platforms for hosting user-generated and studio-produced virtual environments; hosting online virtual environments for entertainment and educational purposes; cloud-computing services featuring software for real-time rendering of photorealistic three-dimensional environments.