Javascript

Javascript is what gives many website's their interactive flavor. It can be used to create menus, rollovers, alpha levels, animations, update content dynamically (updates to a page without having to reload, sometimes refered to as AJAX), and much much more. This language was developed by Netscape back in 1995 and originally called LiveScript. Due to the buzz created by Sun Microsystem's mobile language, Java (originally designed for cellular phones), Netscape decided to rename LiveScript to JavaScript (or so many people think, obviously an idea from Netscape's marketing department).