Makes accessible an adaptable program for projecting age composition and growth of populations. The user specifies time paths for age-specific birth and death rates and the initial population; the program computes demographic characteristics of population over time, including average number of children born and surviving, by age, to women of various ages. Fertility and mortality may be endogenous to the model of population growth; e.g., age-specific birth rates can be a function of average number of children women have. The user may add his own subroutines for linking the projected population structure to labor force participation; migration; household savings; demand for educational, family planning, and health services; and the like. Examples show uses of the program and differences between "stable" populations and actual initial population structures for purposes of demographic projections and policy analysis. 92 pp. Bibliog.