  The formation and evolution of binaries which contain two neutron stars or a
neutron star with a black hole are discussed in detail. The evolution of the
distributions in orbital period and eccentricity for neutron star binaries are
studied as a function of time. In the model which fits the observations of high
mass binary pulsars best the deposition of orbital energy into common envelopes
has to be very efficient and a kick velocity distribution has to contain a
significant contribution of low velocity kicks. The estimated age of the
population has to be between several 100 Myr and 1 Gyr. The birthrate of binary
neutron stars is about 3.4 10^{-5} per year (assuming 100% binarity) and their
merger rate is about 2 x 10^{-5} per year. The merger rate of neutron star
binaries is consistent with the estimated rate of gamma-ray bursts, if the
latter are beamed into an opening angle of a few degrees. We argue that PSR
B2303+46 is possibly formed in a scenario in which the common envelope is
avoided while for the other three known high-mass binary pulsars a common
envelope is required to explain their orbital period.
