The x rendering extension (render) introduces digital image composition as the foundation of a new rendering model within the x window system. rendering geometric figures is accomplished by client-side tessellation into either triangles or trapezoids. text is drawn by loading glyphs into the server and rendering sets of them. the xrender library exposes this extension to x clients.

more information about x.org can be found at:

this module can be found at git://anongit.freedesktop.org/git/xorg/lib/libxrender