BookStore.NET (by Mihnea Radulescu) is a digital book management application using db4o v7.4 and C# 2.0, targeting the .NET Framework 2.0. It allows the user to manage all of its digital books and articles (pdf, chm, html, doc, rtf, etc.) on the computer in an elegant and effective way. Go ahead and check it out because it's cool and even useful. If you want to contribute to the project please check this thread. Thanks Mihnea!