Wenger, White, & Smith's excellent "Digital Habitats: stewarding technology for communities" is now available for free, in major ebook formats!

I really like this book: though it is a bit of a patchwork in places, longer than it needs to be, and heavier on practice than theory, it is an absolute goldmine of ideas for those creating, managing, and nurturing online communities, covering technical, managerial, social, and many other issues in an admirably holistic fashion. Very well written by people that really get it. This is going to be high up among the "highly recommended" readings for my Social Computing course (there are and never will be required readings) because the approach - which gives no special priority to tools, processes, social engagement, management, etc - fits it to a T.