Chapter 13: Appendix

[ Previous chapter ][ This chapter ][ Next chapter ] The following list of multi-user operating systems is neither complete nor expected to be exhaustive. It simply explains some names and terminology. In particular, the UNIX type of operating system comes in two main flavours: Berkley-type of UNIX (somewhat historically as it is no longer exclusively shipped), and the most recent version of UNIX System V , release 4. It should be noted that the operating systems which are generally used on personal computers (DOS, Windows, Macintosh ), do not run a multi-user operating system . The main characteristics of the larger systems are a user identification which is associated with a reserved area on a storage device (hard disk), and access and other privileges associated to the particular computer, such as system management functions. The most privileged user is usually called "root" or "SYSTEM" .

The VMS operating system is a proprietary operating system manufactured by the company Digital Equipment Corporation (DEC). It used to run exclusively on VAX processors, but newer machines of DEC can also run VMS on ALPHA processors (also called AXP processors). The latter can also run the OSF/1 flavour of UNIX (see below). VMS is called OpenVMS today. The most current version as of this writing was VMS 6.1.

The original VAX processors of the company DEC (see above) were also capable of running the ULTRIX operating system, which is another flavour of the UNIX (Berkeley style) operating system. Later, the MIPS processors R3000 and R4000 were used in classic "DEC stations". ULTRIX is currently being phased out, as it is not supported on DEC's new AXP processors. The last ULTRIX version was 4.3 with some alphabetic letter.

The OSF/1 operating system is the most recent variant of DEC's implementation of UNIX on the AXP chip. Most of the former Berkeley-style, and all System V type of UNIX commands are expected to work correctly. The OSF/1 system is available for the AXP chip of DEC. The most recent version of OSF/1 at the time of this writing was 2.0.

The machines produced by the company SUN used to run an operating system which was a classic Berkeley-type of UNIX. Famous architectures like Sun3 and Sun4, but also the early SPARCstations used to run SunOS in a version which was more recently renamed from SunOS 4.x to Solaris 1.x.

The most recent computers built by the company SUN run an operating system called Solaris. This system is mostly System V- like with some earlier Berkeley extensions to enhance backwards compatibility. The most recent version was Solaris 2.5.

The computers manufactured by the company Silicon Graphics run an operating system called IRIX. The current shipping version (5.3 and 6.0, resp.) is System V-type UNIX. IRIX runs on the MIPS type of chip (3000, 4000, 8000 and related).