# Flex is now Open Source - one of the sweetest announcement from Adobe

> Markdown version of https://brajeshwar.com/2007/flex-is-now-open-source-one-of-the-sweetest-announcement-from-adobe/ — 2007-04-26

Adobe is announcing that <a href="http://www.adobe.com/go/flex/">Flex</a> will be released under the <a href="http://opensource.org/licenses/mozilla1.1.php">Mozilla Public License</a> (MPL). Along with <a href="http://www.mozilla.org/projects/tamarin/">Tamarin</a>, Adobe will make Rich Internet Application Development an Open Source Experience. Developers can use the Flex SDK to freely develop and deploy Flex applications using either Adobe Flex Builder or an IDE of their choice.

The <a href="http://www.adobe.com/go/opensourceflex/">Open Source Flex</a> initiative will thus make not only the source of ActionScript components from the Flex SDK, which have been available since Flex 2, but also includes the Java source code for the ActionScript and MXML compilers, the ActionScript debugger and the core ActionScript libraries from the SDK. The Flex SDK includes all of the components needed to create Flex applications that run in any browser - on Mac OS X, Windows, and Linux and on now on the desktop using <a href="http://www.adobe.com/go/apollo/">Apollo</a>.

Sign up for the Google Group discussion on Flex Open Source. You can download the <a href="http://www.adobe.com/products/flex/">Flex SDK</a> too. So, Open Source believers, let's flex our Rich Internet Application Development experience.

Q. Why Adobe chose the Mozilla Public License?

Mozilla Public License was the best one to help remove the concerns of Adobe's customers and other commercial vendors, while retaining the drive to release code changes as the modifications are distributed. It also pairs well into the Tamarin project, which was also released under an MPL license. MPL allows the community to innovate freely, and that innovation will help bring Flex freely into new opportunities and new features.

Q. What is Tamarin?

The goal of the "Tamarin" project is to implement a high-performance, open source implementation of the ECMAScript 4th edition (ES4) language specification. The Tamarin virtual machine will be used by Mozilla within SpiderMonkey, the core JavaScript engine embedded in Firefox, and other products based on Mozilla technology. The code will continue to be used by Adobe as part of the ActionScript Virtual Machine within Adobe Flash Player.