The Galaxy distributed operating system aims at true network transparency both for the local-area networks and for the wide-area networks. The basic mechanism to accomplish this is the three-level object-naming scheme which has many features for reliability, efficiency, and flexibility. Based on this naming scheme, a network-wide virtual address space called the uniform address space is constructed. It facilitates smooth load and information sharing. The mechanisms for unified data sharing and synchronization for this global address space are provided. The provision of static and dynamic data replications is useful for improving both reliability and performance. The process structure of Galaxy is efficient and flexible enough to realize a fine grain of concurrency in single/multi-processor systems. Global process management based on process migration is indispensable for the network-transparent distributed processing. In Galaxy, an object-based environment is implemented on its process-based system architecture. The object group is a key mechanism in an object-based environment to realize hierarchical, integrated object processing and management.