I meant to say "adapted _as a render back-end_ for this".
The pipeline must be: parse SMILES string - generate graph of atoms and bonds (possibly as CML?) - work out 2d/3d structure - generate graphical depiction of structure - render depiction to .PNG graphic (or to SVG as/when widely available?)
It looks like http://www-ra.informatik.uni-tuebingen.de/software/joelib/introduction.html might be the solution to several of these problems. It's GPL / LGPL free/open-source software, reads SMILES, and can generate graphics and do lots of other things.
See http://www-ra.informatik.uni-tuebingen.de/software/joelib/screenshots/java.h... for some screenshots.
-- Neil