MALTED, software to use, create and edit digital textbooks

The Spanish Ministerio de Educación, Cultura y Deporte has a very interesting material at everyone's disposal. Its name is MALTED. There are didactic units made with it that cover all ESO and BAT courses. I think those materials are not enough to replace a textbook, but anyone can edit and modify them, even create new materials to suit their own needs. There are courses on MALTED at formacionenred. If you want to have a look at MALTED, go here.