R version 0.63.2 or later, 0.64 for spatial
R (>= 1.9.0), graphics, stats, lattice, nlme, survival
R (>= 2.4.0), grDevices, graphics, stats, utils
R (>= 2.5.0), grDevices, graphics, stats, utils
R (>= 2.5.0), R (<= 2.9.2), grDevices, graphics, stats, utils
R (>= 2.0.0), graphics, stats, lattice, nlme, survival
GPL (version 2 or later)  See file LICENCE.