  We describe a web-based cgi calculator for constructing synthetic
color-magnitude diagrams for a simple stellar population (SSP) using the
Yonsei-Yale (YY) isochrone data base. This calculator is designed to be used
interactively. It creates quick look CMD displays in (B-V) and (V-I) colors.
Stochastic effects on the CMDs are included. Output in tabular form is also
provided for special purpose displays, or for combining the CMDs of different
stellar populations. This research tool has applications in studies of the
stellar content of our Galaxy and external systems. It provides an easy way to
interpret the CMDs in resolved stellar populations. It offers the means to
explore the dependence of the integrated properties of unresolved stellar
systems on stellar parameters (ages, chemical composition, binarity) and on the
characteristics of their parent population (IMF slope and mass range).
