BookLibrary is a bukkit plugin to manage books on a server. It has quite lots of features e.g uploading,editing books to a database, getting books from there via command or ingame block, book sales with integrated ranking, subscribe functions and many more. Installation is quite as easy as installing any other plugin.
Quote from BukkitDev's staff:Development builds of this project can be acquired at the provided continuous integration server. These builds have not been approved by the BukkitDev staff. Use them at your own risk.
This plugin is released under GNU GPL v3.
