First the good news, I am now a teacher and expert at the Montessori School Potsdam. After a year of testing, I am now responsible for the digital technologies at this school next to my work in the FabLab.
In several courses, I made an introduction for students and course teachers in some tools (which we use) for collaborative documentation and their use in the classroom. One example is Etherpad. I started using this software sevral years ago in my own project-groups . This software is open source and can be installed as a server on almost any hardware.