This library does nothing on it's own and is re-compiled every minecraft version to provide a stable API for several of my plugins of some craftbukkit internals.
Yes, this plugin has been updated to Spigot for Minecraft version 1.12!
All the downloads are versioned with the craftbukkit version they are for, followed by an optional revision number, and then build number. So if you are on Craftbukkit for Minecraft server version 1.4.4, you would look for a version like this: 1.4.4-b1, with the b1 being the build number. (Always get the version with the highest build number for your version of minecraft) If an incompatibility exists in the builds, it also has a number corresponding to the build, like this: 1.4.5-R0.2-b1 would be compatible for all of 1.4.5-R0.2 builds and up for that version of minecraft.
A recent commit to CraftBukkit now requires any plugins that accesses native "net.minecraft.server" or "org.bukkit.craftbukkit" classes to modify its imports for every new Minecraft version update.
This library abstracts these native classes so that whenever Minecraft updates, only this library needs to be updated. Plugins which use this library can potentially be coded to be compatible with multiple versions of Minecraft.
If you have multiple plugins that utilize native Minecraft code, you will now have to update each one of them for each update.
Fortunately, if you use any plugins which utilize this library, you only need to update one plugin for them. Just grab the version of this library made for your Minecraft version and you're done!
JavaDocs: http://javadocs.yu8.me/tuxtwolib/
Thread on how to use the book API: http://forums.bukkit.org/threads/simple-temp-book-api.93562/
A lot of classes taken from: http://forums.bukkit.org/threads/lib-prettyscarylib.110164/
Q. I'm getting this in my console: INFO java.lang.NoClassDefFoundError
A. You downloaded the wrong version of the library, or a version that's compatible with your version of minecraft isn't released yet. Please double check and make sure you got the right download.