PDSIA '99 was the fourth in a series of international workshops on parallel symbolic computing, a basic yet challenging area with wide applications in high-performance computing. As in the previous meetings, parallel symbolic languages and systems were the major topics. However, reflecting the latest advances in distributed computing systems, the workshop also encompassed wider perspectives in parallel and distributed computing for symbolic and irregular applications.Contents:Evaluation StrategiesLanguages and ProgrammingMemory Management and Implementation TechniquesSystems and ApplicationsReadership: Researchers and graduate students in parallel and/or distributed computing and symbolic computation.