Xr provides a vector-based rendering API with output support for the X Window System and local image buffers. PostScript and PDF file output is planned. Xr is designed to produce identical output on all output media while taking advantage of display hardware acceleration through the X Render Extension.
Xr provides a stateful user-level API with support for the PDF 1.4 imaging model. Xr provides operations including stroking and filling Bézier cubic splines, transforming and compositing translucent images, and antialiased text rendering. The PostScript drawing model has been adapted for use within C applications. Extensions needed to support much of the PDF 1.4 imaging operations have been included. This integration of the familiar PostScript operational model within the native application language environment provides a simple and powerful new tool for graphics application development.