WeakAuras
World of Warcraft addon that provides a powerful framework
...Displays based on auras, health, power (mana, rage, soul shards, holy power, etc.), cooldowns, combat events, runes, totems, items, and many other triggers. Preset and user-defined animations. Custom side-effects such as chat announcements or sounds. Grouping, which allows multiple displays to be positioned and configured at the same time. CPU optimizations such as conditional loading/unloading of displays, modularity, etc.