Edje is a complex graphical design and layout engine. It provides a
mechanism for allowing configuration data to define visual elements in
terms of layout, behavior, and appearance.  Edje allows for multiple
collections of layouts in one file, allowing a complete set of images,
animations, and controls to exist as a unified whole.

Edje separates the arrangement, appearance, and behavior logic into
distinct independent entities.  This allows visual objects to share
image data and configuration information without requiring them to do
so.  This separation and simplistic event driven style of programming
can produce almost any look and feel one could want for basic visual
elements. Anything more complex is likely the domain of an application
or widget set that may use Edje as a conveneient way of being able to
configure parts of the display.

WWW: http://www.enlightenment.org/Libraries/Edje.html