ShowSim and FWsim sometimes get mixed up. ShowSim is a pyrotechnic software first released in 2004, and was one of the first software packages of its kind. It features 3D graphics and realistic effects. The software is primarily targetted at professional pyrotechnicians, however, there is also a “Backyard Edition” available for hobbyists. The last version of Show Sim was released in 2015, and no updates have been released since then.
FWsim is a show scripting and visualization software. It started out as a fireworks game and gradually evolved into a pyrotechnic simulation solution that is used by professional fireworks companies in 40 countries. A free trial is available. If you’re shooting fireworks for fun, try the hobbyist edition. If you’re working professionally with pyrotechnics, download the professional edition.