Macromedia introduced Flex in 2004 so that developers could write web applications for the
nearly ubiquitous Flash platform. These applications benefited from the improved design,
usability, and portability that Flex made possible, dramatically changing the user experience.
These features are a cornerstone of Web 2.0, a new generation of Internet applications focused
on creativity and collaboration.
Since the introduction of Flex, Macromedia—and now Adobe—has released versions 1.5, 2, 3,
4, and 4.5 of Flex. With each subsequent version, creating rich, compelling, intuitive applications
has gotten easier, and the bar has been raised on users’ expectations of web applications.
Countless organizations have discovered the benefits of Flex and have built and deployed
applications that run on the Flash platform.
But Flex 1 and 1.5 were most definitely not mass-market products. The pricing, lack of IDE,
limited deployment options, and other factors meant that those early versions of Flex were targeted
specifically for large and complex applications as well as for sophisticated developers and
development. However, with the new releases of the Flex product line, all this has changed.
Flex 2 was released in 2006 and made Flex development a possibility for many more people,
as it included a free software development kit (SDK). With the open sourcing of Flex 3, and
the announcement of free versions of Flash Builder for students, Flex development is within
the grasp of any developer with enough foresight to reach for it. The release of Flex 4 made it
even easier to build rich, efficient, cutting-edge applications, and streamlined the workflow
between designer and developer, greatly easing the process of bringing intuitive, compelling
designs to even more Flex applications. In this latest release, Flex 4.5, Adobe has further
extended the reach of Flex, making it possible to deploy applications not only to browsers and
desktops, but to phones, tablets, televisions, and other connected devices.
Getting started with Flex is easy. Flex itself is composed of two languages: MXML, an XMLbased
markup language, and ActionScript, the language of Flash Player. MXML tags are easy
to learn (especially when Flash Builder writes them for you). ActionScript has a steeper learning
curve, but developers with prior programming and scripting experience will pick it up
easily. Still, there’s more to Flex development than MXML and ActionScript.