Spock can respond to two MIME types, chemical/x-pdb and chemical/x-spock via the helper application webspock. In order for this to work properly, the following lines need to be added to the global mailcap and mime.types files, or the user's $HOME/.mailcap and $/.mime.types. The Install.sh script will do this automatically if it's run as root and it finds /usr/local/lib/netscape, otherwise it will have to be done manually.
# mailcap addition for spock chemical/x-pdb; webspock %s; chemical/x-spock;webspock NULL %s
# mime types for spock command scripts and pdb files type=chemical/x-spock \ desc="Spock command script" \ exts="sp" type=chemical/x-pdb \ desc="Protein Data Bank files" \ exts="pdb"