We will have a book sprint next week to hopefully finish the Etoys reference manual in time for the next release. A book sprint is usually held in some place, where the participants meet face-to-face and spend a weekend or rather a week writing a book.
Unfortunately, we cannot have the physical meeting, but we can do it online. We are using FLOSS Manuals, a web-based tool for collaborative writing. Since we started last December, we already have gained some experience. I like the tool! It will get more interesting when it comes to the design of the pages and cover. Right now, my biggest problem is to find a good structure for the book. It needs to have numbered chapters and sub-chapters to give the reader the context, but on the other hand, too much numbering (like 22.214.171.124.5) isn't help anymore. So we need to find a good balance. Fortunately, with FLOSS Manuals, the layout is made using css, so we don't need to worry about the design yet and can just write.
We have a wiki page with more information about the book sprint here: