Virtualization of the operating system has become an important consideration in the cloud, corporate data center, and academia. With the multitude of available virtualization platforms, careful consideration is needed for selecting the right solution for a specific virtualization application. This research focuses on an analysis of two open source virtualization platforms or hypervisors: Xen and Kernel-based Virtual Machine (KVM). Evaluations are conducted on the basis of overall performance and throughput, virtual machine performance isolation and scalability for use as a host for the Xen Worlds Project. In doing so, the existing Xen Worlds Project infrastructure, middleware, and virtual machines are migrated to KVM to provide a test bed for the evaluation using a benchmark suite and a set of scripts to simulate user behavior.