I have about 8 or 9 wikis set up with pbworks-including one for my family to coordinate calendar events. I like it because every page has a forum already attached for comments. I like ti because I can set levels for participation by my students-all are writers, none are editors. For educators, it is free and there are less ads and they are not inappropriate. I can upload, and so can my students, all types of files. It is so easy that the students need little instruction to make it go.