This book is devoted to the lectures presented at the Sixth International Conference on Formal Power Series and Algebraic Combinatorics held at DIMACS in May 1994. The conference attracted approximately 180 graduate students and junior and senior researchers from all over the world. Generally speaking, algebraic combinatorics involves the use of techniques from algebra, algebraic topology, and algebraic geometry in solving combinatorial problems; or it involves using combinatorial methods to attack problems in these areas. Combinatorial problems amenable to algebraic methods can arise in these or other areas of mathematics, or in areas such as computer science, operations research, physics, chemistry, and, more recently, biology. Because of this interplay among many fields of mathematics and science, algebraic combinatorics is an area in which a wide variety of ideas and methods come together. The papers in this volume reflect the interesting aspects of this rich interaction.