C4 is a creative-coding framework which lets you build expressive user experiences and create works of art on iOS. It gives you the power of the native iOS programming environment with a simplified API which lets you get down to working with media right away. It lets you build artworks, design interfaces, and explore new possibilities of working with media and interaction.
libNUI is a hardware accelerated GUI framework that makes it possible to build rich multi-platform applications based on 3D rendered dynamic layouts. Interfaces are built as a composition of widgets and behaviors, and the framework handles positioning, resizing, anchoring, and texture stretching. Objects are connected with synchronous events and delegates for mono-threaded communication, or asynchronous notifications and message queues are used for multi-threaded applications. It also supports strings (including Unicode), paths, files, data streams, fonts, threads, critical sections, audio buffer rendering, and more.