Autocad
Autocad community featuring training, autocad user support, tips and tricks, tutorials, videos, discussion groups, and cad manager best practices.
http://autocad.autodesk.com/?nd=plant_tips_tutorials
Usa
Download a 30-day autocad trial and learn how to take design further with one of the world’s leading 2d and 3d design and documentation platforms.
http://usa.autodesk.com/autocad/trial
Heidihewett
Advance your autocad software skills to the next level.
http://heidihewett.blogs.com
Esri
Esri is the world leader in gis (geographic information system) modeling and mapping software and technology. this site features gis mapping software, desktop gis, server gis, developer gis, mobile gis, gis web services, business gis, internet mapping, gis solutions, gis training and education, demos, data, spatial analysis tools, consulting, services, partners, customer service, and support.
http://www.esri.com/software/arcgis/arcgis-for-autocad/demos.html
Youtube
Get a first look at the new and enhanced functionality in autocad 2011 with these autocad 2011 fe...
http://www.youtube.com/playlist?list=PLA12DE6B15BE9A463
DXF-DWG Viewer (gb)
Progesoft intellicad, probably the best intellicad distribution in the world. the real autocad alternative to work with dwg
http://www.progesoft.com/compra/index.asp?left=viewer&lang=eng
Autocad 2004 (de)
Autocad 2004 (de)
http://www.cpr.de/cad/acad2000demoindex.html
Freecad (gb)
Freecad (gb)
http://www.freecad.com/