This is not a pure technical question, but I believe answers will help the RIA community.
We are a software development company working on development of a stock trading product. We chose to use Adobe Flex (in mid of 2008) due to its browser penetration and its maturity relative to Silverlight. We already developed the system, and we are quite happy with it.
Now we are planning to launch the second version of our product, and it will feature a much more advanced user interface — basically a framework of dockable windows and panes as in Visual Studio 2005 and onward, etc. We searched on the internet and found that the market of 3rd party components for Adobe Flex is still very small, but for Microsoft's Silverlight there are many advanced 3rd party components available e.g. data grids, docking frameworks, etc.
When can we expect the same type of components in Adobe Flex? What do experts think if we develop to the new version of Silverlight (Expertise in Adobe Flex vs. Silverlight is not an issue at the moment, assuming we have to develop everything from scratch).
The launch of next version is expected to be in mid 2010. Any feedback regarding this is highly appreciated.
Best Answer
I can tell you from direct experience that Flex is a more productive platform. I work for a large RIA consultancy that builds a large number of apps with both Flex and Silverlight and we see that equivalent functionality in SL takes about 10-20% longer to develop than in Flex. Data binding support in Flex is significantly easier to use than in SL. I can also tell you that a suitably-experienced Flex developer could easily build a MDI toolkit in Flex with a couple of weeks of development time. So I would advise you to consider hiring experienced Flex developers rather than shelling out money for SL components.
SL does have a big advantage in that C# can be used on both the client and server and business logic can be reused in both tiers. This is significant and should not be discounted. ActionScript doesn't have a server-side counterpart and lacks this ability, although Flex does play nicely with a number of different backend technologies, especially Java using BlazeDS. Silverlight services integration has a variety of options on the .NET side (see Bart's comment below) while Flex can use very performant AMF in both RPC and data push (messaging). BlazeDS is free and open source.
I also think basing your decision for a development platform solely off the availability of 3rd party components is not a great idea. Putting that aside, MS platforms have always had a huge number of component development shops and a wide variety of components to choose from. It's likely even with a smaller market share that SL will have a bigger selection of 3rd party components than Flex moving forward.
Finally, I don't think MS is going to be giving up on Silverlight anytime soon. They are aggressively developing new features for SL4 and the Blend tool offers some innovations for designer/developer interactions that even Adobe is struggling to match with their new Catalyst tool.
If you have to make the decision today, I'd say go with Flex, especially for a public-facing application where you don't want to lose users because they can't or won't install the SL plugin. In 12-18 months I'm confident that SL will give Flex a much bigger run for its money but I don't think it's there, yet.