It is a batch converter that allows you to convert DWG and DXF to PDF without the need of AutoCAD.
Stand-alone utility - AutoCAD NOT required.
Convert DWG and DXF to vector PDF in batches.
Supports paper space and model space.
Supports every version of DWG/DXF files (Supports R2.5/2.6, to R2005/2006 formats)
Very easy to use.
The "Pro" version supports command line.