Abstract. This paper deals with the design of an API for building distributed parallel applications in C++ which embody strict multithreaded computations. The API is enhanced with mechanisms to deal with highly irregular non-deterministic computations often occurring in the field of parallel symbolic computation. The API is part of the Distributed Object-Oriented Threads System DOTS. The DOTS environment provides support for strict multithreaded computations on highly heterogeneous networks of workstations.