There has recently been considerable research and development in the field of open distributed processing. The goal of this work is to enable access to distributed services without concern for the underlying environment. A number of standards and platforms have emerged to achieve this goal. This paper provides a tutorial introduction to these initiatives. In particular, the paper examines the ISO standard for a Reference Model for Open Distributed Processing, OMG's CORBA and OSF's DCE. The paper concludes that these initiatives are different in scope and should be viewed as complementary. The paper also speculates on a path to convergence between the three initiatives although a number of issues remain to be solved before such a convergence can become a reality.