What is ItemsXL?
Caliburn is an API that allows to save, store and load customized Bukkit items and mobs in their specific state. In short, it does something similar to what Vault does for money and permissions for items and mobs. The following example illustrates the concept:

• Plugin A uses custom item X for a specific purpose that does not accept other items with the same material.
• Custom item X is registered in Caliburn by an admin.
• Plugin B implements Caliburn.
• Plugin B gives items to players when they do something.
• An admin wants to configure B to give X to players sothat they can use it for the purpose specified by A.
• The admin needs to do no more than specifying the registered ID of X in B's config file because B uses Caliburn.

ItemsXL is a basic implementation that offers commands to manage content registered in Caliburn ingame.

See here for more information.

Compatibility
Server
Supported: Spigot for Minecraft 1.8.x and higher

Java
8 and probably higher.

Known incompatibilities
None. An item box system ensures compatibility with all plugins that can add lore lines to items.

Plugins maintained by me
All of them are free and open source
FactionsOne - Factions 1.8.2 with UUID support - updated to latest Bukkit versions!
HolographicMenus - Create GUIs like in Sword Art Online!
DungeonsXL - Create custom dungeons or adventure maps with ease!
CommandsXL - Simple command link plugin.
ItemsXL - Advanced and unique custom item plugin.
BroadcastXS - Async broadcast plugin.