converting of chemical structures into graphical images

I am looking for tools to convert chemical structure files (preferably MDL
 molfiles or Chemical markup Language) into graphic files. As an output
 I am considering
  a) vector graphics [Windows Metafile (WMF) or perhaps the new Stylable
     Vector Graphics format (SVG)]
  b) bitmaps (e.g JPEG)
 I am aware that chemical structure drawing programmes like ISIS/Draw are
 able to
 do this interactively, but I would rather prefer having a tool which can be
 started from the command line or within a script. It would also be nice
 the source code available. The aim is not to generate rendered images, but
 simple structure drawings.
 Any information on such conversion tools would be appreciated.
 I'll summarise the answers
  Ansgar Schuffenhauer
  aschuffenhauer (+ at +)