I have SketchUp Make which is easy as to use and great for designing things that I am not going to print in 3D or CNC etc. I am a hobbyist at the moment and only doing this in my spare time which is why I want freeware, if I get some good designs happening I will then look at buying a program (like rhino or something like that) as I am hopeing to turn this into a business eventually, but that is just a dream at the moment. so I can work on my prototypes safely offline and save only to my offline computer. I am trying to find 3D 'CAD' modelling software, for Mac OS X, that has a free version and can be used offline so my files aren't saved on the 'cloud' or owned by the software company etc.