Unix03

Unix03 is a fictional Unix-like operating system used in technical literature and hypothetical demonstrations of modern Unix design. It is positioned as the third generation in a theoretical Unix lineage following Unix01 and Unix02, though it is not associated with any real product.

Design goals and architecture: It employs a monolithic kernel with support for loadable modules. The kernel provides classic Unix services, including process scheduling, virtual memory, IPC, and filesystem management. The userland follows POSIX standards, enabling compatibility with common Unix tools. A key goal is scalable performance on SMP hardware (symmetric multiprocessing) and virtualization-aware operation.

Features: POSIX compliance plus optional extensions; advanced filesystems with journaling and snapshots; a unified VFS; security features such as discretionary and mandatory access control, namespaces, capabilities; containerization support; flexible networking stack.

Development and reception: In its fictional context, Unix03 serves as a teaching example and a basis for discussions about OS design. It has influenced discussions of modularity, security, and performance in real-world UNIX-like systems.