A/UX
 - Apple
 
AIX
 - IBM
 
Amdahl Open Enterprise Systems
 - Amdahl's SVR4-based native-mode mainframe Unix and large-server edition of Solaris for Sun SPARC servers.
 
BSD OS
 - BSD Incorporated
 
UNICOS
 - CraySoft's
 
Debian GNU/Linux
 - Debian GNU/Linux is a complete and powerful Unix-compatible operating system for IBM PC and compatible machines with an 80386 or faster processor.
 
DG/UX
 - Data General
 
FreeBSD
 - A port of BSD 4.4 Lite to the PC platform with an emphasis on ease-of-installation and stability under heavy load (see also: ftp://ftp.cdrom.com).  Free and with full source, an admin's dream OS for web, ftp and NFS servers, IP gateways and firewalls, home development systems, you name it!
 
HP-UX 10
 - Hewlett Packard
 
IRIX 5.3
 - Silicon Graphics (SGI)
 
Lasermoon
 - Specialists in Unix Freeware such as Linux and FreeBSD and internet connectivity and related software. We are manufacturers, distributors and suppliers for a wide range of products which can be found in our catalogue.
  Lasermoon Catalogue
MachTen
 - Tenon Intersystems produces a BSD UNIX and Mach implementation for Apple Macintosh computers.
 
Minix
 - Andrew Tanenbaum
 
NetBSD
 - 
 
OSF/1
 - Digital Equipment Corporation
 
Santa Cruz Operation (SCO)
 - UNIX operating systems and related solutions for the PC industry and
  Client Integration solutions
Santa Cruz Operation (SCO) - Mexico
 - The Santa Cruz Operation Mexico Web Page
 
Sector7
 - OpenVMS to Unix migration. Includes technical information and white pages.
 
Solaris
 - Sun Microsystem
 
Solbourne Computers
 - Grumman Systems Support, Systems Support corporation is the source for Solbourne computer hardware and software support.
 Web/ftp patches & information, help desk, support.
SPARC64/OS
 - HAL Computer Systems
 
system V
 - Unix for Intel x86 processors.
 
Topix
 - Sequoia Systems
 
UnixWare
 - Novell's UNIX
 
UTS
 - Amdahl's