Name : CraftBook
Link :http://dev.bukkit.org/bukkit-plugins/craftbook/
Why do i Recommend it? Becaaauusseee :
CraftBook is a heavily customizable plugin that adds a number of new mechanics to Minecraft with no client mods required. As one of Minecraft's oldest mods/plugins, we were the first to bring you Minecraft computers, Redstone ICs, moving bridges, and more! Here's a short list:
?Modular, and extremely light on your server.
?Enable features that you need, disable ones that you don't. Even tweak features to your liking.
?Adds heaps of mechanics that allow you to mimic large portions of FTB/Tekkit with a vanilla client.
?Redstone ICs (Logic gates, Sensors, Many others)
?Elevators for your server so people can jump between floors quickly. (Or smoothly, if you choose so)
?Working cauldrons so players can cook inside them.
?Your own custom crafting recipes.
?Hidden switches for players.
?Togglable areas and bridges.
?Chairs you can sit on. (Eli wants this)
?Working pipes that can transfer items from place to place.
?Footprints where your players walk.
?Mobs and players drop their heads.
?The ability to bind commands to items, with cool-downs, permissions and timers.
?And much more... (Seriously, check the wiki)