CAD tip # 4260:

AutoDWF can help in company document management and opens access to the most current versions of AutoCAD drawings both for members of your design team and non-CAD users.

The AutoDWF utility (reactor) can be downloaded from Download, see description in the accompanying documentation and the AutoDWF command.

From the AutoDWF.txt:

On every SAVE/QSAVE/END of your DWG drawing AutoDWF saves/publishes a copy of your drawing to a DWF file. Old version of the DWF file is rewritten with the updated copy. You can setup the target folder for your DWF file and optionally upload it to a FTP or iPROJECT server.
The AutoDWF command can be used to disable/re-enable the auto-publishing functionality (ON/OFF options).
The 'noQS' toggle sets whether the _QSAVE (Ctrl+S) command also publishes DWF or not.
The 'Folder' option sets the target folder/subfolder name.
The 'FolderType' suboption specifies how the 'Folder' name is used - the 'Absolute' setting just uses the 'Folder' name as the target, the default 'Drawing' option saves the DWF copy with the DWG file, 'Current' saves the DWF in the AutoCAD current (Start-In) folder.
The 'Layout' option specifies which layout is published. The default 'Current' means the current layout when the drawing was saved (= mostly Model), 'Model' means "always publish the Model tab", the new '3Dmodel' option published the 3D DWF copy of the model tab, 'Specified' lets you specify a fixed layout name to publish (must exist in all drawings). The 'All' option switches to a different DWF processing - all Layouts (must be initialized) are published to a multisheet DWF file. The new 'Append' suboption will append layout name to PDF filename. The 'Scale' suboption will leave the plot scale to Default (instead of Fit to scale).
The 'Upload' option lets you automatically upload the published DWF to a FTP server or your iPROJECT server.
The option 'Now' performs the DWF publishing on demand (not on save) - even when the reactor is switched Off. You can e.g. call "AutoDWF Now" in your menu macros for final plotting.
The 'Status' option lists current AutoDWF settings.