This is an ever changing industry with many well known products and companies being taken over and merged with others. There are many CAD software products currently on the market. More than half of the market is however covered by the four main PLM corporations Autodesk, Dassault Systemes, PTC, and UGS Corp., but there are many other CAD packages with smaller user bases or covering niche user areas. See also list of free and open-source CAD software.

Packages can be classified into three types: 2D drafting systems (e.g. AutoCAD, Terramodel, Microstation); mid-range 3D solid feature modellers (e.g. Inventor, SolidWorks, SolidEdge, Alibre Design, VariCAD); and high-end[7] 3D hybrid systems (e.g. Pro/ENGINEER, CATIA, NX (Unigraphics)). However these classifications cannot be applied too strictly as many 2D systems have 3D modules, the mid-range systems are increasing their surface functionality, and the high-end systems have developed their user interface in the direction of interactive Windows systems.