StarTip-Rift : Tooltips from the Outer Rift.
StarTip-Rift is is a tooltip addon. It only tries to reproduce the unit tooltip. You can customize by installing a new profile addon that you or someone else writes. Examples exist within the StarTip directory: StarTipDefault and StarTipNatural. You can copy/paste the entire folder to your Addons folder to get started. You'll have to give it a name though, let's say HopeBound.
Here's an example to give you a feel: http://rift.curseforge.com/addons/startip-rift/pages/example-profile/
To load it, type: /startip profile YourProfileName
Type /startip for options, including configurations, proiles, CPU information, ...
Note that StarTip comes with two profiles: Default and Natural.
If you are unhappy with Default, then type: /startip profile Natural
If you wish to create your own profile using this profile as a template, then it's really easy. Check the file StarTipNatural.lua and adjust what you need to customize as you wish. Look under StarTip-Rift's Libs directory and note the LibScriptable-1.0 directory. Look under this directory, and you'll see LibScriptablePlugins-1.0. From there view all the various functions in the sub directories. This is your execution environment organized. The LibScriptablePluginUnit-1.0.lua file is where you might want to start.
Each run environment for each Lua script executed has a couple of special members and variables. Such as _G if you wish to reach the overall script environment. And you have 'self'. And 'unit'. Then everything included from the plugin directory.
Note that each instance of StarTip starts off with a _G, and that is the main script environment. However, we use a special table for each Lua script's environment, and _G doesn't point to that table, but rather to Rift's UI interface script environment, where Inspect.Unit.Detail exists.. So you could call '_G.StarTip:IterateModules()' or '_G.UI.CreateFrame()'. I've tried to add everything from Rift's _G into the user's Lua script's global environment, but I may have missed some things. This is what '_G' is for at this point.
I'm always in #riftuidev on freenode.net, or use this addon's comments to ask questions.