Custom LaTeX letter class based on scrlttr2 from the KOMA script package.
In order to use this class you need a working LaTeX distribution, e.g. texlive,
including xelatex, which is available on most distributions package manager.
Just copy the class file m4letter.cls and fonts folder next to your letter
document and use the following command to create the letter:
xelatex <your-document.tex>
Alternatively, adjust the PROJECT variable to match your documents name in
the included Makefile and simply run
make
The repository includes a demo file example.tex featuring extended commentary
for reference.