An independent portal for the mechanical engineering industry, and software for using and creating such catalogs.
http://www.web2cad.com/
Library of parametric components for 2D/3D CAD assemblies, which can be used with several CAD packages.
http://www.traceparts.com/
A library of 2D and 3D architectural symbols in DWG and 3DS format on CD-ROM [requires Flash].
http://www.modelcad3d.com/
Collection of 3D furniture models in Max3.0 and DXF format, with some free sample downloads.
http://www.kit3dmodels.com/
Human-figure data sets for architectural drawings in DXF, MCD VectorWorks, and EPS format.
http://www.sum-cd.com/
Produces library symbols and footprints for the Cadence CAD software.
http://www.cadpartsusa.com/
A searchable online database of 2D and 3D AutoCAD and 3D Studio models, and portal to manufacturers web sites.
http://www.cadlib.co.uk/
Furniture and accessories in DXF/DWG/3DS/MAX format for use in 3D visualisations for free download for architects and interior designers.
http://www.buildingenvironments.com/