  We present a rapid binary evolution algorithm that enables modelling of even
the most complex binary systems. In addition to all aspects of single star
evolution, features such as mass transfer, mass accretion, common-envelope
evolution, collisions, supernova kicks and angular momentum loss mechanisms are
included. In particular, circularization and synchronization of the orbit by
tidal interactions are calculated for convective, radiative and degenerate
damping mechanisms. We use this algorithm to study the formation and evolution
of various binary systems. We also investigate the effect that tidal friction
has on the outcome of binary evolution. Using the rapid binary code, we
generate a series of large binary populations and evaluate the formation rate
of interesting individual species and events. By comparing the results for
populations with and without tidal friction we quantify the hitherto ignored
systematic effect of tides and show that modelling of tidal evolution in binary
systems is necessary in order to draw accurate conclusions from population
synthesis work. Tidal synchronism is important but because orbits generally
circularize before Roche-lobe overflow the outcome of the interactions of
systems with the same semi-latus rectum is almost independent of eccentricity.
It is not necessary to include a distribution of eccentricities in population
synthesis of interacting binaries, however, the initial separations should be
distributed according to the observed distribution of semi-latera recta rather
than periods or semi-major axes.
