Architectural, interior and engineering symbols, details and blocks on CD-ROM to order, which can be modified for you own use.
http://www.autocadlibrary.com/productinfoautocad.htm
Amethyst CADwizz allows to view AutoCAD DWG and DXF files and to convert between them, on recent Windows systems.
http://www.cadwizz.com/
Shareware for processing DWG files without AutoCAD, recovery service for DWG files that cannot be repaired with AutoCAD.
http://www.intelcad.com/
Menu utilities and interface enhancements for recent AutoCAD versions.
http://www.multicim.com/pmenu.html
Developers of translation and data exchange software used in the STEP translators of many CAD/CAM software vendors, with an online translation service.
http://www.steptools.com/
Offers CADE, a CAD ActiveX control to view and edit 2D vector graphic, with web and DXF support.
http://www.weresc.com/
A standalone tool for the design of AutoCAD hatch patterns.
http://www.fell-kernbach.de/products/ahatch/index-en.html
A powerful, full-featured, award-winning CAD and drawing package. Program has hundreds of commands, tools and options for creating almost any type of CAD drawing. 30-day trial by TommySoftware.
http://www.tommysoftware.com/