Hi everybody, we made RSim available at RSim introduction. This is cross-platform GUI that allows to create GDML from CSG primitives and CAD. It also creates a number of other formats (DAGMC, TetGen, Vsh5, STL and VTK). Using the same interface you can create General Particle Source inputs. The full setup ends up in a GRAS input file. But you will need to obtain GRAS independently as we cannot distribute it. It is a free software, so be gentle and please send bug reports and suggestions. Be especially careful creating tetrahedral data: the underlying Netgen has many parameters and the defaults might not work.