  We develop simple numerical algorithms for both stationary and non-stationary
solutions of the time-dependent Gross-Pitaevskii (GP) equation describing the
properties of Bose-Einstein condensates at ultra low temperatures. In
particular, we consider algorithms involving real and imaginary-time
propagation based on a split-step Crank-Nicolson method. In a
one-space-variable form of the GP equation we consider the one-dimensional
linear, two-dimensional circularly symmetric, and the three-dimensional
spherically-symmetric traps. In the two-space-variable form we consider the GP
equation in two-dimensional anisotropic and three-dimensional axially-symmetric
traps. The fully-anisotropic three-dimensional GP equation is also considered.
Numerical results for the chemical potential and root-mean-square size of
stationary states are reported using imaginary-time propagation programs for
all the cases and compared with previously obtained results. Also presented are
numerical results of non-stationary oscillation for different trap symmetries
using real-time propagation programs. A set of convenient working codes
developed in Fortran 77 are also provided for all these cases (twelve programs
in all). In the case of two or three space variables, {Fortran 90/95 versions
provide some simplification over the Fortran 77 programs}, and these programs
are also included (six programs in all).
