Space Gass is described as 'SPACE GASS is a multi-purpose 3D analysis and design program for structural engineers. Its extensive range of features make it suitable for anything from beams, trusses and frames to buildings, towers, tanks, cable structures and bridges' and is an app. There are more than 50 alternatives to Space Gass for Windows, Linux, Web-based and Mac. The best Space Gass alternative is RodX, which is free. Other great apps like Space Gass are Robot Structural Analysis Professional, Etabs, SAP2000 and Abaqus Unified FEA.