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
GEOS (8-bit operating system) fully reverse-engineered and rewritten as C for the cc65 compiler suite. The reverse-engineered source code has been made available at Github. Dozens of official and third-party applications and other products were produced for GEOS. Among the most important and popular were the following: GEOS (8-bit operating system) GEOS ("Graphic Environment Operating System") is a discontinued operating system from Berkeley Softworks (later GeoWorks). Originally designed for the Commodore 64 and released in 1986, it provides a graphical user interface for this popular 8-bit computer. GEOS closely resembles early versions of the classic Mac OS and includes a graphical word processor (geoWrite)