Operating systems

Windows
Linux
FreeBSD
CentOS
Red Hat
Android
Symbian
Windows Mobile

Programming languages

Microsoft  ASP.NET, C#,VB.NET  
PHP
AJAX
JavaScript
VBScript
Ruby on Rails
Flash (ActionScript)
COM / DCOM
CSS
SOAP
SSL
MAPI, TAPI, SAPI
HTML / DHTML, XHTML
XML / XSLT
VML 
OLE, ActiveX
TCP / IP, HTTP / FTP, SMTP, POP3, IMAP
Perl
Python

Java programming technologies

J2SE, J2EE (EJB, JSP, JSF, JTS, JMS, JAAS, JAXP, JAX-WS, Java time services)
JBoss Seam
BPM (jBPM, ALBPM)
AJAX
HTML/DHTML

Microsoft programming technologies

NET (ASP.NET, WinForms, ADO.NET, Enterprise Services)
MS SharePoint
AJAX
XML/XSLT
HTML/DHTML

Web and Application Servers

BEA Weblogic
JBoss
BES
Sun Glassfish
Apache
Tomcat, Resin
Microsoft IIS
MS Exchange Server
SharePoint Server
Flash Media Server
Lotus Domino Server

Database Management systems (DBMS)

Oracle
Microsoft SQL Server
Hypersonic
MySQL
MSSQL
PostgreSQL
Sybase Adaptive SQL Server (ASA / ASE)
Derby
MS Access
IBM DB2

Reporting systems

Crystal Reports / Crystal Reports Enterprise
Eclipse BIRT
Jasper reports

Integrated Development Environment (IDE)

Microsoft Visual Studio .NET
JBoss developer studio (Eclipse)
IntelliJ Idea
Sun NetBeans
BEA development Studio (Eclipse)
CodeGear LiveSource (Eclipse)
Altova Mission Kit
Oxygen

Modeling methodologies / CASE tools

UML
Sybase Power Designer
Rational Unified Studio
Microsoft Visio
CodeGear LiveSource / Together
Enterprise Architect
CA ErWin

Methodologies

XP / SCRUM
RUP
AUP

VoIP

SIP
RTP (RTCP)