McXtrace - Monte Carlo ray tracing simulations of X-ray experiments. McXtrace is a tool for simulating X-ray instrumentation and experiments using a ray-tracing formalism. Currently the main use of McXtrace is in the field of synchrotron beamline instrumentation design, but various other uses have been found, for instance for designing X-ray telescopes or for laboratory sources. This port contains the McXtrace component library. WWW: http://www.mcxtrace.org