Not only is this a great piece of software to store your own personal book collection in a good looking way, but it's also a fully functional lending library. Groups, circles, covens, groves, etc. can employ this tool to lend out books to their members. The catalog can even be exported as a web file to be published. Members could view the online catalog, email the library owner, and then have the book brought to them at the next group gathering. It couldn't be simpler.
Circle members studying towards initiations may not have to purchase the required books if other members were willing to lend them out. Libra personally makes me feel a little bit more secure in knowing where my books are.
The best part of the whole thing is that Libra is free. I've been searching for something like this for ages. By the way, I am in no way affiliated with Libra. I just love the product. There also appears to be a lot of room for expansion on this product. You can even customize the background. My screenshot above has glass shelves (default to Libra) and my own pretty wallpaper pattern. Click the image to make it bigger and you'll notice that Goddess for Hire is marked OUT. This is because a circlemate borrowed it from me over the weekend. Now I'll know where this book is and when it was borrowed.
Cool stuff. Check out their website and give it a shot. There are loads more features that I didn't mention for you to explore and play with.