This was my 2012-2013 attempt at fufilling some ideas of a "progressive textbook" design: one that grows with the reader, and gradually offers more-complicated nuances.
I especially liked the graphics that went into this. I formed all of them either with either Inkscape or Blender. For the rest, I took photographs. In some articles are real interactive SVGs (completely self-contained in code, and self-made in drawing).