## Drop vs Tether

Drop is a library built on the [Tether](http://github.hubspot.com/tether) positioning engine. 
Tether is intentionally designed to only handle positioning. You give it an element and a
target, and it keeps the element where you want it relative to the target.

Quickly it became clear that while that simplicity allowed Tether to be more powerful,
many of its use cases required a few more concepts.  Specifically, Drop adds the following
on top of Tether:

- The concept of the element being 'opened' or 'closed', and the ability to link events
to the opening and closing.
- Element creation handled for you by Drop. Drop adds a 'drop-content' element inside of it
to make styling easier.
- A simpler attachment syntax that assumes you always want to place the drop in one
of twelve positions outside the target.
- A class on the body to allow you to style elements differently when a drop is opened.
- CSS themes with nice arrow-y bits and animation

It's very possible that a sufficiently complex application will eventually outgrow
Drop and move to using Tether directly. You can always pass `tetherOptions`
to your Drop instance if you need more explicit control of Tether's behavior.