3.1 Xml - namespaces - flex 4  (Page 2/8)

What is Flex?

As mentioned above, Flex is an XML-based programming language that is used to create programs that execute in Adobe's Flash Player. In order to understandFlex, and particularly the differences between Flex 3 and Flex 4, we need to start with the Flash Player and work backwards to Flex.

What is the Flash Player?

According to the Flash Player website:

Adobe Flash Player is a cross-platform browser-based application runtime that delivers uncompromised viewing of expressive applications, content,and videos across screens and browsers. Flash Player delivers breakthrough web experiences to over 98% of Internet users.

Flash Player is widely available

Many of the popular websites that people frequently visit require that the Flash Player be installed on the local computer in order to view the material onthe website.

Typically if you visit a website that requires the Flash Player and you don't have it installed on your computer, you will be guided through the installationprocess. Therefore, a very large percentage of computers already have the Flash Player installed.

An execution engine

In short, the Flash Player is an execution engine that is used to execute or play programs that are written in the ActionScript programming language. (See Baldwin's ActionScript programming website .)

What is ActionScript?

According to the ActionScript Technology Center,

"Adobe ActionScript is the programming language of the Adobe Flash Platform. Originally developed as a way for developers to program interactivity,ActionScript enables efficient programming of Adobe Flash Platform applications for everything from simple animations to complex, data-rich,interactive application interfaces.

First introduced in Flash Player 9, ActionScript 3.0 is an object-oriented programming (OOP) language based on ECMAScript -- the same standard that isthe basis for JavaScript -- and provides incredible gains in runtime performance and developer productivity."

What is the Adobe Flash Platform?

According to Adobe Flash Platform ,

"The Adobe Flash Platform is an integrated set of technologies surrounded by an established ecosystem of supportprograms, business partners, and enthusiastic user communities. Together, they provide everything you need to create and deliver the most compellingapplications, content, and video to the widest possible audience."

The primary delivery mechanisms for applications built with the Adobe Flash Platform are the Adobe Flash Player and Adobe Air .

What is Adobe Air?

According to Adobe Air ,

"The Adobe AIR runtime lets developers use proven web technologies to build rich Internet applications that run outside the browser on multiple operating systems."

Once again, what is Flex?

Flex is an XML-based programming language that can be used to create ActionScript programs for execution in the Flash Player . When you compile a Flex project, it is first converted into an ActionScript program and theActionScript program is compiled into a form suitable for execution by the Flash Player.