Xu is a C++ GUI library driven by 3 core design principles:

• Minimal Instrusiveness: Xu shouldn't have an direct hooks into the rendering or application layer. It should simply receive input and ouput rendering data (renderer agnostic).

• Customizable: Escape hatches where possible so that anything can be changed and anything can be created.

• Maximal Support: Xu should be able to receive mouse input, touch input, stylus input and any other form of primary input and handle it accordingly with relation to widget interactions.