  Strongly correlated quantum impurity problems appear in a wide variety of
contexts ranging from nanoscience and surface physics to material science and
the theory of strongly correlated lattice models, where they appear as
auxiliary systems within dynamical mean-field theory. Accurate and unbiased
solutions must usually be obtained numerically, and continuous-time quantum
Monte Carlo algorithms, a family of algorithms based on the stochastic sampling
of partition function expansions, perform well for such systems. With the
present paper we provide an efficient and generic implementation of the
hybridization expansion quantum impurity solver, based on the segment
representation. We provide a complete implementation featuring most of the
recently developed extensions and optimizations. Our implementation allows one
to treat retarded interactions and provides generalized measurement routines
based on improved estimators for the self-energy and for vertex functions. The
solver is embedded in the ALPS-DMFT application package.
