Algorithms are a central concept in computer science. The German Science Foundation (DFG) started a special jointinitiative on data structures and efficient algorithms in1986 with the aim of encouraging collaborative research onalgorithms. For a period of five years about a dozenprojects were funded with an emphasis on algorithms and datastructures for geometric problems, on the one hand, andparallel and distributed algorithms, on the other.This volume contains 18 papers that are intended to give animpression of the achievements of this joint researchinitiative. The first group of papers addresses research onfundamental data structures, computational geometry, graphalgorithms, computer graphics, and spatial databases. Thesecond group of papers centers on the following problems:the design of parallel architectures and routing strategies,simulation of parallel machines, and the design ofdistributed algorithms for solving difficult problems.