Javascript

Javascript is probably the most popular client-side scripting language used on the Internet today. It can be used to validate forms, cookies development, creating dynamic pages, and much more. Here's some sites that'll get you cooking with Javascript:

Note: Javascript should not be confused with Java.

JavaScript Resource Center

Provides information about the use of javascript as well as several basic javascripts that can be copied.

Javascript Tutorial

For the beginner who has heard of javascript, but never used it before.