| Abstract: | In this paper we describe an operating system for a workstation designed and implemented by the authors within two and a half years. It includes memory management and module loader, a file system, a viewer system, editors for text and graphics, a compiler, a server interface and various tools. The primary motivation was to demonstrate the feasibility of a small, yet highly flexible and powerful, system, a system that is a (decimal) order of magnitude smaller than commonly used operating systems. This is possible due to regularity of concepts and concentration on the essential. The benefits are not only fewer resources needed, but elegance and generality of concepts resulting in transparency and convenience of use and increased reliability. A corner-stone of this approach is genuine extensibility, which is achieved by a new language, in particular by a facility called type extension. It allows for the integration of variables (objects) of a new, extended type in structures of elements of an existing base type. |
