SAOTrace is a suite of software designed to simulate the as-built performance of grazing-angle X-ray optics using the ray-tracing approach. It is derived from portions of the NASA OSAC (Optical Surface Analysis Code) software suite. It can model nested conical as well as flat optical designs, and includes the ability to model arbitrary support structures and baffles. It can model non-ideal multi-layer reflective coatings as well as scattering from the optical surfaces.
WCSLIB is a C library, supplied with a full set of Fortran wrappers, which implements the "World Coordinate System" (WCS) standard in FITS (Flexible Image Transport System). It also includes a PGPLOT-based routine, PGSBOX, for drawing general curvilinear coordinate graticules, and a number of utility programs. The FITS "World Coordinate System" (WCS) convention defines keywords and usage which provide descriptions of astronomical coordinate systems in a FITS image header.