For my company, I generate contracts using troff on Plan 9. The contracts all contain my digital signature - that is, a postscript image of my signature - like so:
.BP /usr/a/Pictures/sigs/signature.ps .5 "" "" "" l I generate postscript for these documents like so: troff -mm -mpictures foo.mm | lp -d stdout | addpsfonts > foo.ps
