Gerber to DXF converter
Another answer suggested an excellent solution for:


  those who looking free way to convert gerber to dxf can try gerbv and pstoedit
  
  install gerbv and pstoedit first convert your gerber to ps through gerbv and >then using pstoedit export it to dxf

gerbv -x ps mygerber.GTS  
pstoedit -f dxf output.ps mydxf.dxf  

  
  remember pstoedit need ghostscript to work


But an important improvement to the pstoedit is to add the -mm option so that the file generated will be in mm and not in pxls.  In my case I made it into a ps2dxf.BAT file that is: 

pstoedit -f dxf:-mm %1.ps %1.dxf


and a name.ps file is converted with:  ps2dxf  name