CAD systems allow an engineer to view a design from any angle with the push of a button and to zoom in or out for close-ups and long-distance views. In addition, the computer keeps track of design dependencies so that when the engineer changes one value, all other values that depend on it are automatically changed accordingly.

Until the mid 1980s, all CAD systems were specially constructed computers. Now, you can buy CAD software that runs on general-purpose workstations and personal computers.

Autodesk Inventor: Revolutionizing Digital Prototyping - Get To Market Faster with Software That Enables You To Create, Test, and Iterate Your Models in 3D.

Nerdworld's CAD software page 
This CAD resource page contains links to CAD software and related newsgroups.

ACCEL Online
Home page for ACCEL Technologies, developers of CAD software for the development of printed circuit boards. There are links to their products, technical support and company information.

Artwork Conversion Software home page
The Artwork Conversion Software home page offers information on their CAD translation products and services, support, and company information.

Ashlar CAD software products
Home page of Ashlar, which develops and sells CAD software products.

Bentley Systems home page
Provides company, industry and product news and information, as well as links to their MicroStation engineering software product, user groups, publications, and international offices.

Graphisoft home page
Graphisoft develops and markets architectural CAD software for Macintosh and Windows platforms. Their home page offers links to their products, technical support, company information and news, and a QuickTime VR gallery.

OrCAD home page
The OrCAD site features the OrCAD Express for Windows product, company news, and technical information.

Router Solutions home page
The Router Solutions site provides links to their line of CAE/CAD/CAM interface products, tools and services.

Video for Windows Runtime installation notes
Contains installation instructions for Video for Windows Runtime for Microsoft Windows 3.1.

Yahoo!'s CAD software page
Yahoo!'s directory of CAD software.

Yahoo!'s Electronic Computer Aided Design (ECAD) page
Yahoo!'s directory of Electronic Computer Aided Design (ECAD).