Finally I finished translating all text on www.musictheory.education.
Also, I almost finished checking all pages and exercises on musictheory.education. Things I have to check are all links to chapters and exercises, the lightboxes with images and text, all exercises, bookmarks and much more.
And I made some improvements. For example I improved the exercises result scale.
I celebrate the official opening of www.musictheory.education on 1st July 2017!