The PC-IRAF release should install and run on any recent Linux or FreeBSD system. Linux is evolving rapidly however, and there are a number of different Linux distributions out there - Slackware, Red Hat, Debian, and others. These are all basically the same thing and they all share the same Linux kernel but they differ in many details regarding what non-Kernel software is included and how it is configured. FreeBSD on the other hand is controlled by a core group of programmers and there are no variant distributions which may conflict.
Unlike the earlier Linux/IRAF port, the V2.11 PC-IRAF distribution contains a single IRAF system (directory tree) which will run on a number of different operating systems, where each host system is represented as a different binary architecture. As of this writing the PC-IRAF V2.11 system contains binaries for Slackware Linux, Red Hat Linux, and FreeBSD. Other architectures will be added in a future release, e.g. Solaris x86 and MkLinux (for the PowerPC Macintosh). Our expectation is that the statically linked linux binaries will run on any recent Linux system, however in general it is not possible to compile programs on a Linux system unless the IRAF libraries have been tailored for and compiled on the target system, due to numerous minor differences in the different flavors of Linux. Different Linux distributions such as Slackware and Red Hat are for all practical purposes different operating systems, except that they share the same Linux kernel.
Before installing PC-IRAF, one must 1) obtain an appropriate PC-IRAF distribution, e.g., from the IRAF network archive on iraf.noao.edu (or by ordering a tape or CD-ROM distribution from NOAO), 2) select the server or node on which the system is to be installed and arrange for sufficient disk space to hold the system, and 3) set aside sufficient time to do the installation. If these directions are followed carefully and mistakes are avoided the basic installation should only take a few minutes on a fast PC. Additional time may be required to customize the system, to configure the local tape drives and other devices, set up IRAF networking, and so on.
The amount of disk space required to install a full IRAF system depends upon the system configuration, including the number of layered packages installed on top of the core IRAF system. The main system, including both the core IRAF system and NOAO package sources, requires from 32 to over 200 Mb depending on what architectures or other options are installed. See the PC-IRAF README for more information on installation options.