This thesis tackles the idea of virtualization and virtual machines. Theoretical part covers basics of virtualization from various aspects. It introduces a concept of virtualization and various architectures used to achieve it. The thesis also examines most popular implementations of mentioned architectures as well as commercially available virtualization solutions using those implementations. The aim of its practical part is to design and implement desktop application for administrator level overview over virtual environment running on oVirt. The main goal is to solve some of its known issues regarding accessibility of its data.