The Photon Simulator (PhoSim) version 4.0 is complete. PhoSim is a fast ab initio detailed physics Monte Carlo code that propagates light through the atmosphere, telescope, and detector systems. This particular version includes a large number of new features. There is a new GUI that you can get running by simply doing:
There is also now a drastically simplified catalog interface, simple catalog generators, and a wide-range of physics improvements.
Full details of the announcement and the code can be found here: