Operating System
+ Linux: Gentoo, Ubuntu, Fedora Core, OpenSUSE
+ Unix: FreeBSD, OpenBSD
+ Mobile: Symbian
+ Microsoft Windows: Microsoft Windows 95/98, 2000, XP

Networking
+ TCP/IP
+ Routing, Switching
+ WLAN

Software development platform
+ J2ME
+ .NET
+ Nokia Symbian

Web development platform
+ LAMP
+ Tomcat
+ IIS

Database
+ Oracle
+ MySQL
+ Microsoft SQL Server
+ SQLLite
+ Microsoft Access

Programming language
+ Assembly
+ C, C++, C#
+ Haskell
+ Esterel
+ Java
+ Pascal
+ Python
+ Perl
+ Visual Basic

Scripting Language
+ PHP
+ ASP
+ JSP
+ bash
+ JavaScript
+ ActionScript
+ AJAX

Markup Language
+ HTML
+ CSS
+ XML

Graphic design
+ Adobe Photoshop
+ Adobe Illustrator
+ Adobe Fireworks
+ GIMP

Animation
+ Adobe Flash
+ Flex

Office
+ Microsoft Office
+ OpenOffice