Solaris
Mostly Solaris 9, 10, 11
Mostly Solaris 9, 10, 11
Mostly Oracle, RHEL and its clones
Cloud stuff
Debian and clones
shell, perl, some other scripting
Suse distro
Networking
HP-UX version 11.23 and 11.31
Mostly External storages
Quick tips for every day work ...
miscellaneous ...
databases ...
Monitoring, like Nagios, etc ...