Cad Software

A9CAD

http://www.a9tech.com

Tinycad - The open source schematic capture program for windows

http://tinycad.sourceforge.net/

FreePCB - Free, Open source printed circuit board layout editor for Microsoft windows

http://www.freepcb.com/

Turbocad

http://www.turbocad.co.za/

NTE Electronics

http://www.nteinc.com/

NTE Download

http://nte01.nteinc.com/webforms.nsf/qcsignin?openform

How Stuff Works

http://www.howstuffworks.com/

Orcad

http://www.orcad.com/

Ivex - Winboard/Winspice

http://www.nteinc.com/cad/

Autocad

http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=2704278

Smartdraw Software

http://www.smartdraw.com/specials/caddrawing.asp?id=11927

Free Cad Software

http://www.freebyte.com/cad/cad.htm