Which API should I use: JavaScript, Flex, or Silverlight?

All of the ArcGIS Web Mapping APIs are similar in functionality and Esri is committed to supporting them equally. The choice of which API to use should be driven by your or your organization’s preference towards one of the three development environments – JavaScript, Flex or Silverlight. Typically, we’ve found that organizations lean toward the API where they have the most experience and existing expertise. As with all development, your customer’s needs may be the ultimate factor for choosing one API over the other.

Nevertheless, here are some simple guidelines that might make it easier for you to make a decision:

ArcGIS API for JavaScript

• The ArcGIS API for JavaScript is considered by many to be our simplest API for embedding maps into web sites. You don’t need to be a hardcore developer; all you need is a text editor and a browser to get started. Most developers familiar with HTML are also familiar with JavaScript, so this API might help you get started faster.
• This API uses pure HTML and JavaScript – no add-ins to your browser are required. Apps created with this API load fast and perform very well.
• Developers who use JavaScript have access to many JavaScript libraries and frameworks. For example the Dojo framework includes charting tools, buttons, and common controls. There are also free web-based development environments such as Aptana Studio.

ArcGIS API for Flex

• This API leverages great web design tools from Adobe. You’ll be able to create rich, fun to use, web applications that you can build once and run across all supported browsers.
• Developers can take advantage of the robust Adobe Flash Builder development environment and there’s an extensive market for Flex components that accelerate the creation of applications. Along these lines, ArcGIS Server features an optimized output format for Flex called Action Message Format, which accelerates queries to the GIS server. This API is also a friendly environment for Java developers.
• Users of your Flex applications will require the Flash browser plug-in, which is perhaps the most ubiquitous browser plug-in. However, some devices don’t currently support Flash.

ArcGIS API for Silverlight

• If you’re a .NET developer, this is the API for you. You’ll be able to create rich, fun to use, web applications that you can build once and run across all supported browsers.
• Developers can take advantage of the great Microsoft development environment. The API is built on the Microsoft Silverlight platform, which is integrated with Visual Studio 2010 and Expression Blend 4. The Microsoft Silverlight platform includes a lightweight version of the .NET Framework CLR (CoreCLR) and the Silverlight runtime - all hosted via a browser plug-in.
• Users of your Silverlight applications will require the Silverlight plug-in. While the technology is relatively new, the market for Silverlight components is growing. However, some devices don’t currently support Silverlight.

My Preference 

ArcGIS API for Flex is most using API at present in Web development, i continue working on this api, it will be my first choice as it as its own developer community.


ArcGIS API for JavaScript is best choice for mobile development along with HTML5 & Phone Gap.
at present HTML5 is not as mature as Flex  , but good scope in future ,i am working on ArcGIS API for JavaScript for smart phone apps.


ArcGIS API for Silverlight is now growing may be good in future, but it has its own Preferences. at present it is my least choice