AutoCad WS is a free cloud-based service from AutoDesk (registration required) that lets you upload, view, share, edit and download AutoCad files (DXF and DWG) online; there are also apps for remote viewing and editing on Android and iPhone smartphones. You currently can’t create a new file in the editor, but you can either create a DWG/DXF file using a free editor like DraftSight and upload it, or take a currently existing file, edit it to remove all features, then save it as a different name.
This is by no means a substitute for the full version, but it does contain a fair subset of the basic functionality, with drawing/editing/annotation tools, and layer support:
Even though one of the sample drawings included is labeled “Geospatial Sample”, there’s no native support for georeferencing or geospatial coordinates. If you load in a file with geospatial information, add/edit features, then save it, it will maintain the geospatial referencing.
If your file is in some form of Mercator coordinates, like UTM, you can calibrate/reference fairly accurately it against a Google Maps view in the app. Here’s a rough DXF outline of Indian Island in Eureka, CA, traced from a UTM topo map, and uploaded to AutoCad WS:
From View, I turn on a Google Maps background; this also brings up a control for aligning the drawing with the background:
The feature fills the screen, and obviously isn’t calibrated to the correct location. Using the Search Box, I can bring up the Google Maps view of Eureka, CA, then use the Place/Scale/2 Points/Rotate functions to align the outline with the actual island:
Pressing Apply locks the scale and orientation of the drawing data to the Google Maps view. Any new features I now add will be positioned correctly in the Google Maps view. Even without this Google Maps calibration, these new features would have the correct geographic coordinates and placement if I export the drawing file back to my computer.