The ToM (thread on modules) microkernel

The authors have been developing a distributed operating system called Threads on Modules (ToM). It supports a programming model which is suited for distributed environments. For this purpose, modules, threads, houses, users, RPCs and capabilities are introduced. To make the ToM system as portable as possible, it was implemented using the microkernel technology. The ToM microkernel implements the minimal functionalities and the others are implemented as user level programs. Although the ToM microkernel is designed to support the ToM programming model, it has sufficient functionalities to implement other operating systems. This paper presents some of the main features of the ToM microkernel. A UNIX emulator also is presented.