a component system that will provide extensibility and re-usability both inside and between applications, while being portable across platforms (and languages) and having the lowest possible overhead (both in machine resources and programming effort).
a 2D graphics library, support for multiple output devices. (output targets include the X Window System, Win32, image buffers, PostScript, PDF, and SVG file output. Experimental backends OpenGL (through glitz), Quartz, and XCB.