In the past five years, distributed operating systems research has gone through a consolidation phase. On a large number of design issues there is now considerable consensus between different research groups. In this paper, an overview of recent research in distributed systems is given. In turn, the paper discusses overall system structure, protection issues, file system designs, problems and solutions for fault tolerance and a mechanism that is rapidly becoming very important for efficient distributed systems design: hints. An attempt was made to provide sufficient references to interesting research projects for the reader to find material for more detailed study.