The book contains a collection of articles in theoretical computer science, written by leading authorities in the field. The topics range from algorithms and complexity to algebraic specifications, and from formal langauges and language-theoretic modelling to computational geometry. The material is based on columns and articles thathave appeared in the EATCS Bulletin . In spite of the fact that very recent research is discussed, the largely informal style of writing should make the book accessible to readers with little or no previous knowledge of the topics.