

3D CAD software systems are used to assist in the creation, modification, analysis, or optimization of a design. The software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing.

SolidWorks:
SolidWorks is a 3D mechanical CAD program that runs on Microsoft Windows. SolidWorks is currently used by over 2 million engineers and designers at more than 165,000 companies worldwide.
Solid Words Website

SketchUp:
SketchUp is a 3D modeling program with a broad range of applications such as architectural, civil, mechanical, film as well as video game design. The highlights of the program are its ease of use and online repository of model assemblies known as 3D Warehouse. The online model directory enables designers to locate, download, use and contribute free models.
Sketchup Website

Auto CAD:
AutoCAD is a software application for computer-aided design (CAD) and drafting. The software supports both 2D and 3Dformats. AutoCAD software is now used in a range of industries, employed by architects, project managers, and engineers, amongst other profession.
Auto Desk Website

Rhinoceros:
Rhinoceros (Rhino) is a stand-alone, commercial NURBS-based 3D modeling software. The software is commonly used for industrial design, architecture, marine design, jewelry design, automotive design, CAD / CAM, rapid prototyping, reverse engineering, product design as well as in the multimedia and graphic design industries.
Rhinoceros Website