HTML/XHTML

HyperText Markup Language and Extensible HyperText Markup Language are the backbone language of most webpages. Scripting languages (such as php, VB.net, C#, ASP, JSP, ColdFusion) are very polular, but still rely on basic html to deliver content in a given space. One notable exception is ActionScript which uses a flash container to deliver its content.

PHP and ZEND Zend Framework, Zend Studio

PHP, the scripting language running on 25 million webservers world wide, was created to deliver fast, dynamic webpages with excellent reliability, funcationality and speed. As a mature language, version 5 offers a myriad of supported functions and strong database support. Zend Solutions offers a reliable development environment and the optimized Zend framework.

FUSE (MVC Framework)

A robust MVC platform for object oriented PHP. Influenced by the Ruby on Rails and CakePHP frameworks, with added customization and intuitive features, FUSE can rapidly create a working Model/View/Controller structure to properly organize an application. More at FUSE.net

MYSQL

One of the fastest and most reliable Relational Database systems, MYSQL is now owned by SUN Microsystems and is poised to be the leading contender for database system development in the decades to come.

JavaScript

JavaScript started off as a light weight scripting language to add dynamic content and interactivity to webpages. Now it is mostly used as a client-side supporting language for form checking and AJAX (see below). The advantage of JavaScript is that the processing is done on the client's machine. The disadvantage is it's unreliable secuity.

AJAX - Asynchronous JavaScript and XML

AJAX has gained popularity recently from it's use by Google and other major websites. Not a new language, but a new method for delivering dynamic content to webpages.

ActionScript 3.0 and FLASH

Adobe's newest icarnation of the FLASH language, "AS3" is by far the best and most complete language for use within Adobe's FLASH environment.