=================================== UNIX
============== DB
Postgresql
MySql
H2
============== Monitoring and statistics
SNMP, Icinga, Nagios
Cacti
============== Storage and backup
LVM,RAID
DRBD,NBD
Iscsi
NFS,Clusterfs,Lustre,Samba
Bacula
============== Email
Exim, Postfix
Dovecot
Powermta
Google APPs
============== Authentication
Ldap
Kerberos
Samba
============== Web
Tomcat, Apache
Nginx, Memcached, HAproxy
============== Scripting
Bash, Perl
HA cluster
Linux terminal server project (LTSP).
====================== ============= Development environment
Bamboo, Jenkins (hudson)
Jira
Confluence
Crowd
Maven, Ant
Git, Mercurial , SVN
Artifactory, Nexus
=================================== Networking
Ethernet
vlan
trunks and bonding
802.1x
Tunneling
IPSEC
OpenVPN
GRE
WIFI: OpenWRT and DD-wrt, WDS networks
Firewals and good knowledge of TCP/IP
Network installation and diskless workstations
=================================== Hosting
Hetzner
Rackspace
Amazon
=================================== Virtual environments
Vmware infrostructure
Citrix xen server
Proxmox
Openvz
KVM, XEN
Virtualbox