To build this document, if you have 'make' and 'awk', simply give the command:

  % make

If you don't have make and awk, then:

  % unzip unity-grammars.zip
  % pdflatex VOUnits

(or equivalent).  The file known-units.tex is generated from
unity-grammars/known-units.csv, but is checked into the repository so
that it can be build by hand in this way.