WRATH is a library to facilitate drawing user interfaces with GL in an optimized fashion. It does not address window creation or event handling for that matter. It only handles drawing and creation of objects that represent that drawing. To that end WRATH can be made to work in a variety of toolkits that allow drawing with OpenGL or OpenGL ES.

WRATH is a data based library; UI items and widgets by their existence have their content presented to the screen. The items and widgets themselves do NOT have a paint method. Instead, how they are drawn and what they draw is data and that data is assembled by WRATH into common units to reduce CPU load on drawing.

WRATH provides the following features for UI drawing

• text rendering and formatting
• image, gradients and brushes
• paths: filling and stroking
• transformation hierarchy system allowing for user defined transformation node types
• a set of classes that allows one to create new item types drawn with one's shaders that will work on an transformation node type using the transformation hierarchy system of WRATH
• a set of classes to apply brush (image, gradient, etc) linearly and non-linearly to items

and more.