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Dave McAllister SourceForge Editorial Staff

Flex SDK Versions

The Flex SDK was open sourced as of version 3.

Version | Last Milestone or Stable Release (download)

Flex 4.6 | November 29, 2011

Flex 4.5.1 | June 19, 2011

Flex 4.5 | May 2, 2011

Flex 4 | March 21, 2010

Flex 3 | December 11, 2009

Flex 4.6

Flex 4.6 is the next major step in cross-platform mobile application development and offers several new components and functionality specifically designed to help developers create applications for the latest mobile and tablet devices.

Flex 4.5

The 3 primary themes of Flex's next release, code-named, Hero, are:

  • Multi-Screen Development: Allow developers to build applications that target the web, desktop or mobile devices using a single unified framework.
  • Spark Maturation: Polish and grow the Spark architecture by adding new Spark components and capabilities.
  • Large-Application Development: Support developers building large applications by improving fundamental pieces of the Flex infrastructure.

More details

Flex 4

As of March 21, 2010, Flex 4 has been released. It is has 3 primary themes:

  • Design in Mind: provide a framework meant for continuous collaboration between designer and developer.
  • Developer Productivity: improve compiler performance and add productivity enhancements to language features like data binding
  • Framework Evolution: take advantage of new Flash Player capabilities and add features required by common use-cases

More details

Flex 3

Flex 3 was initially released on February 25, 2008. It was focused in 4 areas:

  • Designer/Developer workflow: e.g., enhanced constraints, Flex Component Kit for Flash CS3
  • Working with data: e.g., list effects
  • Adobe AIR applications: support in the framework for Adobe AIR features
  • Platform evolution: e.g., persistent framework caching, compiler performance

More details


Wiki: Download Flex 3
Wiki: Download Flex 4.5
Wiki: Download Flex 4.6
Wiki: Download Flex 4