GIF files allow any web browser to view the image easily, but without pan and zoom capability. As with ARC/INFO, a screen capture program can be used to grab images from the screen while running AutoCAD and then save it as a GIF file. We haven't done this.
We have tried to convert DXF files to GIF files with programs such as HiJaak and CorelDRAW. In each case there have been problems with the result.
Release 13 of AutoCAD includes a new SAVEIMG command that allows saving drawings as GIF (and other formats) directly. This works well. Images appear identical to the original AutoCAD images when viewed with Netscape. Of course, the GIF files aren't scalable, but at the same scale, the results are identical.
There are at least two vector choices, DWG and DWF files. Vector formats have the big advantage of allowing panning and zooming. GIFs are like toys in comparison.
DWF (Design Web Format) is a file format proposed as a standard by Autodesk for making AutoCAD drawings available on the web. DWF files are optimized for web viewing. They are smaller than DWG files, can contain URL links, and allow you to distribute an image while keeping your DWG files proprietary, if you wish.
See Viewing AutoCAD DWF Images for DWF viewing options. See Autodesk's Publishing DWFs and Serving AutoCAD DWF Images for publishing DWF's. Pima County's Parcel Maps (Landbase maps) were generated with these Autodesk tools. They also demonstrate URLs embedded in the DWFs and integration with a tabular database. Since the Release 13 Internet Publishing Kit, AutoCAD has been able to create DWFs with the DWFOUT command.
CADViewer offers a way you can serve DWF files without requiring a plug-in. CADViewer uses a 100% Java applet rather than a plug-in, enabling viewing on any Java-enabled platform without any special user action.
If your web server software supports the generation of automatic directory listings, you can publish your DWG or DWF library just by pointing to it's root directory. You may choose to keep both DWG and DWF formats in the same directories.
To serve DWG files, it is usually necessary to configure your web server for the correct MIME type for DWG files. Otherwise, browser plug-ins won't recognize the drawing files. For instance, for Internet Information Server version 4, right-click on the server name to get its properties. Then set the "Associated Extension" to
.dwg
and set the "Content Type (MIME)" to
image/vnd.dwg
For Internet Information Server versions 2 and 3, you need to edit the registry. Other web servers have different procedures for setting MIME types.
Here's the complete list of MIME types recommended by Autodesk for their files:
.dwg image/vnd.dwg
.dxf image/vnd.dxf
.dwf drawing/x-dwf
Other DWG MIME types of image/x-dwg and drawing/x-dwg are in use by some web servers, but they don't appear to be the currently official registered DWG types.