Polyacetylence, (CH)_x is the simplest conjugated polymer. Prestine polyacetylence is a good insulator, whereas its highly doped version exhibits metal-like electrical conductivity. This book gives a detailed introduction to this rapidly-developing field is given along with a collection of original papers. The main purpose is to help chemists and physicists grasp the main ideas and most important facts; an expert may also find it useful as a reference volume.