  We present a new open-source program, DCore, that implements dynamical
mean-field theory (DMFT). DCore features a user-friendly interface based on
text and HDF5 files. It allows DMFT calculations of tight-binding models to be
performed on predefined lattices as well as \textit{ab initio} models
constructed by external density functional theory codes through the Wannier90
package. Furthermore, DCore provides interfaces to many advanced quantum
impurity solvers such as quantum Monte Carlo and exact diagonalization solvers.
This paper details the structure and usage of DCore and shows some
applications.
