Latest news (Feb 26, 2011): We've made a first release! http://forums.bukkit.org/threads/6250/ CraftBook is being ported! Source code (for the port) is found here: https://github.com/sk89q/craftbook/tree/refactor (It may or may not be completely up to date.) Also, perhaps MIDI playing ICs? http://www.youtube.com/watch?v=tIIai11JYR8 --- CraftBook's a SMP plugin that adds: Integrated circuits Programmable logic chips Redstone toggleable areas Redstone bridges and doors Bunch of other redstone stuff Minecart boosters, sorters, and other control blocks Minecart behavior modification Some mods that came after CraftBook have some similar features (BridgeMod, ControllerBlock, etc.).