Cairo is a multi-platform library providing anti-aliased vector-based
rendering for multiple target backends. Paths consist of line segments
and cubic splines and can be rendered at any width with various join
and cap styles. All colors may be specified with optional translucence
(opacity/alpha) and combined using the extended Porter/Duff
compositing algebra as found in the X Render Extension.
Cairo exports a stateful rendering API similar in spirit to the path
construction, text, and painting operators of PostScript, (with the
significant addition of translucence in the imaging model). When
complete, the API is intended to support the complete imaging model of
PDF 1.4.