The goal of the Amoeba project was to construct an operating system for networks of computers that would present the network to the user as if it were a single machine. An Amoeba network consists of a number of workstations connected to a "pool" of processors, and executing a program from a terminal causes it to run on any of the available processors, with the operating system providing load balancing.[3] Unlike the contemporary Sprite, Amoeba does not support process migration.[5]
The workstations would typically function as networked terminals only. Aside from workstations and processors, additional machines operate as servers for files, directory services, TCP/IP communications etc.[3]
Amoeba is a microkernel-based operating system. It offers multithreaded programs and a remote procedure call (RPC) mechanism for communication between threads, potentially across the network; even kernel-threads use this RPC mechanism for communication. Each thread is assigned a 48-bit number called its "port", which serves as its unique, network-wide "address" for communication.[3]
The user interface and APIs of Amoeba were modeled after Unix and compliance with the POSIX standard was partially implemented; some of the Unix emulation code consists of utilities ported over from Tanenbaum's other operating system, MINIX. Early versions used a "homebrew" window system, which the Amoeba authors considered "faster ... in our view, cleaner ... smaller and much easier to understand", but version 4.0 uses the X Window System (and allows X terminals as terminals).[3]
The system uses FLIP as a network protocol.
