IRAF is the Image Reduction and Analysis Facility, a general purpose software system for the reduction and analysis of scientific data. IRAF includes a selection of programs for general image processing and graphics applications, plus a large number of programs for the reduction and analysis of optical astronomy data within the NOAO package. External or layered packages are also available for the analysis of HST, XRAY, and EUV data. IRAF provides a programming environment which includes the Command Language script facility, the IMFORT Fortran programming interface, and the SPP/VOS programming environment in which the portable IRAF system is written.