Spectrum is a suite of great and easy-to-use models for policy research that includes DemProj, which carries out cohort-component population
projections. From the Spectrum website: "DemProj projects the population for an entire country or region by age and sex, based on assumptions about
fertility, mortality, and migration. A full set of demographic indicators can be displayed for up to 50 years into the future. Urban and rural projections
can also be prepared. A companion model, EasyProj, supplies the data needed to make a population projection from the estimates produced by the Population
Division of the United Nations." While data is provided for many nations, users can also easily put in their own detailed data.
Applied Demography Toolbox