Rhino5
Download link: http://www.rhino3d.com/download/rhino/5/latest
Rhino 5.0 is the market leader in industrial design modeling software. Highly complicated shapes can be directly modeled or acquired through 3D digitizers. With its powerful NURBS based engine Rhino 5.0 can create, edit, analyze, and translate curves, surfaces, and solids. There are no limits on complexity, degree, or size.
Grasshopper
Download link: http://www.grasshopper3d.com/page/download-1
For designers who are exploring new shapes using generative algorithms, Grasshopper is a graphical algorithm editor tightly integrated with Rhino’s 3D modeling tools. Unlike RhinoScript or Python, Grasshopper requires no knowledge of the abstract syntax of scripting, but still allows designers to build form generators from the simple to the awe inspiring.
PLEASE NOTE: Although Rhino and Grasshopper are available for Mac, these are outdated versions, so it is recommended that you use Windows. If you are interested in dual-booting Windows and macOS on a Mac, I recommend using Boot Camp. More information on Boot Camp can be found here: https://support.apple.com/boot-camp.