One of the problems with Free books is that not just the writing falls to the author. They typically also do answers to exercises, marketing, and here layout.

One of the problems with Free books is that not just the writing falls to the author. They typically also do answers to exercises, marketing, and here layout. It is unrealistic to expect that one person will be able to do those all. (All this goes double if the text is significantly interactive.) I know that there are people who do well in all categories, but expecting that all Free texts will have such authors means expecting that there will be few such texts. There needs to be a way for people who have skills in such areas, and who believe in a project, to get together.