This Installation Guide is intended for sites installing IRAF on a DEC Alpha system running Digital Unix V4.0 or later. The system is expected to work on OSF1 V3 platforms although there may be problems compiling external packages or local IMFORT programs; sites are urged to upgrade if at all possible. Other popular UNIX systems for which IRAF is available, e.g. AIX, HPUX, IRIX, SunOS, Solaris, etc. have their own system specific IRAF installation guides. There are also separate installation guides for the DECstation or VAXstation running Ultrix. The IRAF distribution for the DECstation is DSUX and that for the VAXstation is VXUX. The VMS/IRAF distribution is known as VMS5 and is intended for VAX hardware (an OpenVMS V2.11 version of IRAF for the DEC Alpha is still pending as of this writing). The DEC Alpha Digital Unix IRAF distribution described here is known as DUNX (Digital Unix) in the IRAF archives.