We use different technologies for different things. Like:

• Design
  Adobe Creative Suite
• Development
  Server Side Scripting: Java, PHP, ASP, .Net, SQL
  Client Side Scripting: JavaScript, JQuery
  Multimedia Scripting: Flash
• Web Analytics & Measurment Systems
  Google Analytics, Piwik
• Content Management Systems (CMS)
  Expression Engine, EZ Publish, Drupal, Word Press
• eCommerce Frameworks
  Magento, Zen Cart
• Application / Web Servers and Middleware
  Apache Tomcat (Servlets), Struts, Apache, IIS
• Databases
  MySQL, Microsoft SQL Server, Oracle
• Servers/Operating Systems
  Linux (different distributions), Apple Server, Windows Server