  The code IAC-star is presented. It generates synthetic HR and color-magnitude
diagrams (CMDs) and is mainly aimed to star formation history studies in nearby
galaxies. Composite stellar populations are calculated on a star by star basis,
by computing the luminosity, effective temperature and gravity of each star by
direct bi-logarithmic interpolation in the metallicity and age grid of a
library of stellar evolution tracks. Visual (broad band and HST) and infrared
magnitudes are also provided for each star after applying bolometric
corrections. The Padua (Bertelli et al. 1994, Girardi et al. 2000) and Teramo
(Pietrinferni et al. 2004) stellar evolution libraries and various bolometric
corrections libraries are used in the current version. A variety of star
formation rate functions, initial mass functions and chemical enrichment laws
are allowed and binary stars can be computed. Although the main motivation of
the code is the computation of synthetic CMDs, it also provides integrated
masses, luminosities and magnitudes as well as surface brightness fluctuation
luminosities and magnitudes for the total synthetic stellar population, and
therefore it can also be used for population synthesis research. The code is
offered for free use and can be executed at the site {\tt
http://iac-star.iac.es}, with the only requirement of referencing this paper
and crediting as indicated in the site.
