I use a GNU/Linux OS, Debian/Gnome distribution with emacs/org-mode, Inkscape and Gimp. I make A4 .pdf documents with Inkscape and should start sharing the materials in addition to pictures on mediagoblin.
I should blog about FS2FT: Free Scripting To Free Teaching, the S could be Software and the T could be Teachers.
I teach I.A. Richards's English Through Pictures(EP) books with the Graded Direct Method(GDM).