USU (operating system) of USU includes a very long list of educational apps, like as Celestia space simulator, MuseScore music score typesetter, Blender 3D rendering software, Kalgebra mathematical calculator, and much more. USU haves this approximate system requirements: USU (operating system) USU linux (Bulgarian: УСУ; Учи Свободен с Убунту) is Bulgarian open source desktop operating system built around the KDE desktop environment and based on the popular free Linux distribution, Ubuntu. Usu can be downloaded in three flavours, Desktop, Mini and Netbook, each one with its own features and target audience. All of them can be downloaded for free, as Live CD/DVD ISO
Operating-system-level virtualization system's resources. They include: The operating system may be able to allow or deny access to such resources based on which program requests them and the user account in the context of which it runs. The operating system may also hide those resources, so that when the computer program enumerates them, they do not appear in the enumeration results. Nevertheless, from a programming point of view, the computer program has interacted with those resources and the operating system has managed an act of interaction. With operating-system-virtualization, or containerization, it is possible to run programs within containers, to which only parts