Physics with very high-energy $e^{+}e^{-}$ colliding beams

This report consists of a collection of documents produced by a study group on large electron-positron storage rings (LEP). The reactions of interest in the weak, electromagnetic and strong interactions are discussed. The technical feasibility of the relevant experiments is investigated by attempting, in each case, the design of an experimental set-up. Event rates are estimated using currently prevailing theoretical models and by extrapolation of results at present accelerators. A number of technical reports previously issued by members of the LEP Design Study Group are included as appendices.