USU (operating system) 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 images, supporting 32-bit and 64-bit processors. The defult language is Bulgarian, but in installation it can be easy changed with F2 key. USU Desktop is created to be used as a learning tool, this edition
Darwin (operating system) in Terminal will show the Darwin version number, and the command uname -v will show the XNU build version string, which includes the Darwin version number. Due to the free software nature of Darwin, there are many projects that aim to modify or enhance the operating system. OpenDarwin was a community-led operating system based on the Darwin system. It was founded in April 2002 by Apple Inc. and Internet Systems Consortium. Its goal was to increase collaboration between Apple developers and the free software community. Apple benefited from the project because improvements to OpenDarwin would be incorporated into Darwin releases;