The UNIX and Linux Forums
System administration, shell programming and scripting, hardware and software issues.
Just Some Stuff
A wiki full of useful Unix and storage tips, procedures and how-tos.
Tek-Tips: General UNIX Discussion Forum
Technical support forums and mutual help system for computer professionals. Selling and recruiting forbidden.
The UNIX System
A webpage by The Open Group that holds the UNIX trademark and manages UNIX licensing program.
Command line, shell scripts, SSH.
Solaris, Linux, Vmware, Redhat Linux and veritas volume manager/cluster tutorials. Also shares a real time production issue on those products and sharing the solutions. Free e-books.
Unix how-tos, tutorials, guides, news, tips and tricks.
A port of UNIX Version 7 to the x86 (IA-32) based PC.