Frequently Asked Questions (FAQs)

What is the Apache Flex project?

Apache Flex is the open source continuation of the development of Flex. This includes members of the Adobe Flex team as well as Flex community members at large (or small).

What is Flex?

Flex is a highly productive, open source framework for building and maintaining expressive web applications that deploy consistently on all major browsers, desktops and operating systems. It provides a modern, standards-based language and programming model that supports common design patterns suitable for developers from many backgrounds. Flex applications run in the ubiquitous Adobe® Flash® Player and Adobe® AIR™.

You can use the Flex SDK to create a wide range of highly interactive, expressive applications. For example, a data visualization application built in Flex can pull data from multiple back-end sources and display it visually. Business users can drill down into the data for deeper insight and even change the data and have it automatically updated on the back end. A product configuration application can help customers navigate the process of selecting or customizing products online. And a self-service application can guide customers through an address change or help employees complete an otherwise complicated multi-step benefits enrollment.

In addition to the Open Source Flex SDK, there are useful tools for enhancing the application development experience such as the debug version of the Adobe Flash Player runtime and Adobe AIR for deploying applications outside of the browser. There are also professional IDE's such as Adobe Flash Builder FDT, Flash Develop and more. source

The Flex applications can be written in ActionScript and/or MXML (ie Macromedia XML).

Flex is:

  • a set of skinnable user-interface components with a component lifecycle:
  • a set of services (HTTPService, WebService, RemoteObject)
  • has Managers to handle:
    • Styling
    • Skinning
    • Layout
    • Localization
    • Animation
    • Module-loading
    • User interaction management
  • has accessibility support
  • Flex has an Automation-Testing Framework
  • Flex SDK provides a compiler
What are the goals?
  • Provide a framework that optimizes the strengths of designers and developers to create compelling, expressive applications.
  • Provide a language and tools that allow developers to maximize their productivity when building rich Internet applications.
  • Promote a development model that supports building and maintaining applications across a large number of team members.
What are the Apache Flex community goals?

The immediate goals of the Apache Flex project are to succeed with the next steps of the incubator program: release a version. Further release goals depend on the input of the community. There is no roadmap as of today but there is a general consensus to complete Flex 4 Spark. While not conclusive that means creating a component set of Spark components (parity with mx). Discussions on optimizing all the Spark components in the same way as the Flex 4.6 mobile components were optimized. On going effort is being made to add full support for the Mustella testing framework. Mustella is the name of the testing suite used internally by Adobe. There is also effort to refactor the framework where testing has been impossible.

Who is using Flex?

We are. And you have probably already used a Flex application without knowing it. Flex applications can be run in the browser through the Flash Player runtime, packaged as a native Windows, Mac or Linux desktop application with native installer and mobile devices including Android and iOS as native applications. Fortune 500 companies as well as independent developers use Flex.

What tools are available?

Flash Builder
Flash Develop

Where do I get help using Flex?

There are multiple resources online to help learn and use Flex:

Does Flex cost money?

No. The Flex SDK is free for both personal and commercial use. You can compile your projects using the Adobe mxmlc compiler which is included with the Flex SDK download. Some of the tooling costs money.

Is Flex Open Source?

Yes. Apache only hosts open source projects.

How do I get involved?

Getting Started - Start here to get familiar with the Apache process, the mailing lists, and the community.

Where do I submit a feature request?

You can submit feature requests to the Jira server.

Where do I submit a bug request?

You can submit bug requests to the Jira server.

How do I submit a patch?

A video tutorial on Compiling and Contributing to ApacheFlex using IntelliJ is available here

How do I become a committer?

Become a Part - Its easier to join the process than you think!

Where are the examples?

There is no compiled set of examples available at this time but many are available in . We are in search of people who will contribute and manage them.

What is the road map of the Flash Player?

The Adobe Flash Player is not released or maintained by the Apache Flex project. There is a whitepaper available at Adobe.

What is the road map for Apache Flex?

The roadmap for Adobe's support for Flex is here. Apache projects believe in letting the committers decide what features to add and bugs to fix. In a sense the committers themselves have their own roadmaps. By participating you can become a committer. It's best to ask on the mailing list to see what people are working on.

Will the Flash Player be supported on my mobile or tablet device?

The Adobe Flash Player is not released or maintained by the Apache Flex project. Please put inquiries to Adobe.

Does Flex publish to Windows 8 mobile devices?
Does Flex publish to Android?

Yes. Flex applications can be deployed to Android in two formats: The first, which results in a smaller file size, require the user to install or have installed the AIR runtime to their device (through the Android market). The second, which results in a larger file size, does not require the AIR runtime to be installed. It does this by bundling in the AIR runtime with your application. There are tutorials online on how to install and test applications on Android.

Does Flex publish to iOS?

Yes. Flex applications can be deployed to iOS. It does this by bundling in the AIR runtime with your application. There are tutorials online on how to install and test applications on iOS.

Does Flex publish to BlackBerry Playbook?

Yes. There are tutorials online on how to install and test applications on Playbook.

Does Flex publish to the Mac App store?

There are tutorials online on how to configure and deploy your application to the Mac App store but it is not officially supported at this time.

Where is the Flex and AIR documentation?

The official documentation is here

Where is the ActionScript reference documentation?

The official documentation is here

What is HTML5?
How does Flex compare with HTML5 / JS?
Will Flex target HTML5 / JS?
What work is being done to target HTML5 / JS?
Are there any obstacles to targeting HTML5 / JS?
Is the Flash Player open source?


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  1. Anonymous

    Love Flex and writing mobile apps with it. If Flex supports making HTML 5 apps along with mobile apps that compile natively, it will extend its life indefinitely IMO... I really hope that Flex supports HTML 5 sooner than later. From the FAQ here, however, I can't tell whether this is in the works or not.

  2. Anonymous

    Will the Apache Flex project provide/support an Eclipse plugin?