This is a pretty small mod that adds customizable health bars to mobs. Unlike most health mods, this one is completely server-side.
The health bars' looks and information can be customized in the mod's properties file. The properties file is generated in your .minecraft/config directory.
Unfortunately, I must discontinue this mod. It just does not seem very useful to have server-sided health bars (that do not even work on named entities). In addition, the changes to health in 1.6.2 made this mod more trouble than it was worth.
I never implemented the uninstall feature to remove health bars added by this mod, so use at your own risk. If you uninstall the mod (or update past 1.5.2), entities that had health bars will not lose them, and the health bars will (of course) cease to function.
I may, in the future, make a client-side-only version of this mod, as I rather liked the look, customization, and distance restriction of this mod. We will see. - Father Toast