Abstract: Software architecture for developing distributed fault-tolerant systems independent of the underlying hardware architecture and operating system. Systems built using architecture components are scalable and allow a set of computer applications to operate in fault-tolerant/high-availability mode, distributed processing mode, or many possible combinations of distributed and fault-tolerant modes in the same system without any modification to the architecture components. The software architecture defines system components that are modular and address problems in present systems. The architecture uses a System Controller, which controls system activation, initial load distribution, fault recovery, load redistribution, and system topology, and implements system maintenance procedures. An Application Distributed Fault-Tolerant/High-Availability Support Module (ADSM) enables an applications( ) to operate in various distributed fault-tolerant modes.