  We present r-Java, an r-process code for open use, that performs r-process
nucleosynthesis calculations. Equipped with a simple graphical user interface,
r-Java is capable of carrying out nuclear statistical equilibrium (NSE) as well
as static and dynamic r-process calculations for a wide range of input
parameters. In this introductory paper, we present the motivation and details
behind r-Java, and results from our static and dynamic simulations. Static
simulations are explored for a range of neutron irradiation and temperatures.
Dynamic simulations are studied with a parameterized expansion formula. Our
code generates the resulting abundance pattern based on a general entropy
expression that can be applied to degenerate as well as non-degenerate matter,
allowing us to track the rapid density and temperature evolution of the ejecta
during the initial stages of ejecta expansion. At present, our calculations are
limited to the waiting-point approximation. We encourage the nuclear
astrophysics community to provide feedback on the code and related
documentation, which is available for download from the website of the
Quark-Nova Project: http://quarknova.ucalgary.ca/
