Its intended use to let you print Scheme programs in a way that's visually pleasing. The grinder typesets your code by ignoring all horisontal spacing, while respecting vertical spacing. This means that program lines correspond to what you have in your file. The gringer then imposes its own rules to decide the indentation level. This is a known limitation of my grinder, and Ill fix it when I get a chance.
Every fifth line is numbered and the line numbers run through all the pages.
Also notice that the quote symbol on line 10 is also in Helvetica, to reflect the fact that it's quasiquoted, and therefore, data. It's the grinder. That's all there is to it. The grinder is written in postscript and is meant to be concatenated to the Scheme source you wish to print. The file grind.ps is 43K only, consisting of about 1800 lines of text-only PostScript code, so you can, theoretically, email the file as text if you don't like sending attachments.