AcroPlot Pro converts multiple file formats (DOC, XLS, DWG, TIFF, BMP, PLT, CALS, etc.) to PDF and DWF, in single file and batch modes. http://www.cadzation.com
Converters from the CGM Computer Graphics Metafile format to several other common formats and back, on Windows and unix systems. http://www.cgmlarson.com/
LinkCAD is for converting and viewing CAD formats, supporting GDS-II, DXF, CIF, Gerber RS-274X, PostScript, AutoCAD and other formats. http://www.linkcad.com/