Abstract: A higher order language-directed computer architecture particularly adaptable for fourth generation program languages. The computer includes a memory which stores package modules and task modules for programs, each of which includes a control segment representing control for the module, a code segment representing instructions for the computer relating to the module, a data segment, a type segment representing type descriptors declared for the module, a queue segment containing synchronization messages for controlling queuing between task modules and an import segment containing lists of objects outside a module which are accessible within the module. The computer simultaneously manipulates portions of the segments based on instructions in the code segment.