PyRAF is a command language for IRAF based on the Python scripting language that can be used in place of the existing IRAF CL.
For more information on PyRAF - release notes, installation instructions, the FAQ, tutorials and other documentation, etc. - please visit:
If you are in a great hurry and are installing a stand-alone PyRAF download, visit:
http://www.stsci.edu/resources/software_hardware/pyraf/pyraf_install_src.html