Telecommunications/ Networking

TCP/IP, VoIP, IPSec, NAT, VPN, VPRN
IPv6, SNMP, LDAP, MPLS
IPX, LAN/VLAN, MPLS, SSH

Mobile

iPhone/iPad, Blackberry, Android, Symbian, Meego, 
Windows Phone, Windows Mobile, webOS

Embedded

VxWorks, Linux/Real-time Linux, IP Service Operating System
Device Drivers and Firmware

Programming Languages

C/C++, Java, C#/ASP.NET, PHP, Perl, Unix Shell Scripts

Database

SQL Server, Oracle, MySQL, PostgreSQL

Web Technologies

ASP.Net, ASP, JSP/Servlet, PHP, Perl
AJAX
C#, VB.Net, Java, Python, Ruby on Rails
Web services

Open Source

Joomla, Druple, OpenERP, ..

Product Verification & Validation

WinRunner, Silk, QA Run, JUnit, Robot Test, LoadRunner, Apache Workbench, SmartBits, Quality Center, TeamTrack, Bugzilla