The GNOME canvas is an engine for structured graphics that
offers a rich imaging model, high performance rendering, and a
powerful, high-level API.  It offers a choice of two rendering
back-ends, one based on Xlib for extremely fast display, and
another based on Libart, a sophisticated, antialiased,
alpha-compositing engine.  Applications have a choice between
the Xlib imaging model or a superset of the PostScript imaging
model, depending on the level of graphic sophistication
required.

gail (also available at http://www.slackbuilds.org/) is
required to build this package.