List of Adobe Flex Alternatives

List of Adobe Flex Alternatives
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Adobe Flex Alternatives for Rich Internet Applications

The search for an Adobe Flex alternative has occupied most web designers and developers since it was released in March 2004. Why did this capture their attention and why the need for an alternative?

What is Adobe Flex?

Adobe Flex is a must-know software development kit (SDK) if you are interested in building and deploying a cross-platform Rich Internet Application and making extensive use of the Flash platform. Rich Internet Applications (RIAs) are web applications that perform very similarly to your desktop applications, usable either by way of a site-specific browser, through a browser plug-in, or independently via sandboxes or virtual machines. Adobe Flash, Java, and Microsoft Silverlight are the current top three frameworks.

The Flex SDK comes with a set of out of the box user interface components including buttons, list boxes, trees, data grids, text controls, and various layout containers. Charts and graphs are also made available as an add-on. Other very useful features like web services, drag and drop, modal dialogs, animation effects, application states, form validation, and other interactions round out the application framework.

How does Flex work?

Usually a Flex application serves as the presentation tier. But unlike page-based HTML applications, Flex applications provide many useful ways to send and load data to and from server-side components without requiring the client to reload the view.

Now you are probably asking if it’s that powerful a development kit, why the need for an alternative? Well before Adobe released the Flex 3 SDK under the open source Mozilla Public License in February 2008, this SDK cost a lot of money. This, in turn, forced start-up companies and freelancers to go looking for more options and they found several Adobe Flex alternatives; namely Curl, OpenLaszlo, Ajax, XUL, JavaFX, and Windows Silverlight.

Let’s discuss three of the most popular Adobe Flex alternatives:


Curl is an enterprise Rich Internet Application (RIA) Platform promising the most powerful and effective environment for rapidly developing complex, industrial-strength Web applications. By using Curl, companies can create a new class of Web based feature-rich applications that provide all of the rich interactivity, functionality and performance of client-server applications. Unlike Java, Ajax and .Net, Curl has a rich feature set that combines program logic, graphics, and text processing in one RIA framework. The only detraction to this powerful and enterprise-level SDK is the price tag.


OpenLaszlo is an open-source platform for the development and deployment of Rich Internet Applications. It’s released under the Open Source Initiative-certified Common Public License by Laszlo Systems. Well-known users of OpenLaszlo-powered RIAs are Earthlink, Verizon, WalMart, IBM WebSphere, Yahoo!, Behr, Pandora, La Quinta Hotels and

Ajax (Asynchronous JavaScript and XML) is a collection of interrelated web development techniques used on the client-side to create interactive web applications. By using Ajax, web applications can retrieve data from the server asynchronously in the background without interfering with the behavior and display of the current page. With Ajax the interactive or dynamic interfaces on web pages and applications has increased significantly.