How can you say it is a draw? Some flash applets run 10 times faster than the SL ones on my Mac.

Really? On my computer (MacBook Pro, OS X 10.5.4, Firefox 2.0.0.16) they run at the same speed. As far as I can tell there is no difference at all.

I wonder what other people are finding?

They seem about the same to me. Sometimes the Flash seems faster, sometimes the Silverlight. And then I close the sample and reopen and they again seem different. So, obviously no conclusiveness one-way or the other, because the only real thing that matters is how the given demo runs on a machine, and for each given demo, they seem to do what they do.

BTW, I'm on XP, FF 3.01, FP 10 beta, and an old-a#$ centrino 1.6 from circa 2004.

Silverlight isn't working. That's the usual experience I got by this plugin. Some apps are doing well, the most aren't working. Maybe because of the version jungle? The Most recent version I (had to) install(ed) was the one of the ryianair website with the flightmap app (it's crappy).

I'm using Firefox 3.01

Both seem to be very close in performance. Of course, all these tests only test those features that they both support. Expressive stuff like drop shadows, glows, blend layers, bitmap caching, etc. is where Flash really shines and SL has nothing that can match that.

Richard, thx for describing my blog in this article.

I think both technology have their pros and cons, and I will leave the final judgement to the readers.

What I don't see, is the time to create each and the issues involved to get them to perform exactly the same. When you look @ Flex vs SilverLight, Flex , using FlexBuilder 3, provide a more 'integrated' development experience vs SilverLight where, if you use VS 2008, only provide 'read only design view' -- thus you need Blend. MS will eventually catch up, but I don't believe Adobe will stand pat either -- with Flex being OpenSourced, that will certainly help.

My experience with both (and I've been doing .NET since the first Beta) it Flex is more advanced from a development experience -- FlexBuilder is more 'VS like' that VS 2008. Also when utilizing Caringorm and WebORB, you can really get a good picture for building scaleable RIA.

What I don't see, is the time to create each and the issues involved to get them to perform exactly the same. When you look @ Flex vs SilverLight, Flex , using FlexBuilder 3, provide a more 'integrated' development experience vs SilverLight where, if you use VS 2008, only provide 'read only design view' -- thus you need Blend. MS will eventually catch up, but I don't believe Adobe will stand pat either -- with Flex being OpenSourced, that will certainly help.

My experience with both (and I've been doing .NET since the first Beta) it Flex is more advanced from a development experience -- FlexBuilder is more 'VS like' that VS 2008. Also when utilizing Caringorm and WebORB, you can really get a good picture for building scaleable RIA.

Performance wise they both seem the same to me. The only differences I saw was often the Flash version would appear immediately while the Silverlight one was still loading. I suppose the order on the page may have something to do with that.

I noticed aliasing problems in one Silverlight application that the Flash one did not have but in a later comparison this was switched.

And as John says, this only compares features both have. I mostly know the things that Flash can do now that Silverlight cannot but are there features that Silverlight has that Flash cannot do? Plus I would be interested in a proper comparison of all the features once Flash CS4 and Player 10 are official.

For now I guess we're still at "use whichever suits your needs" or "use whichever has the features you need".

There is something I never seen in Flash. For example, if there is no Flash plugin installed, can Flash display the image showing how the Flash should look if you download the plugin? In Silverlight, there is an easy way to do it by adding to the DIV where the SL install button appear. One good example is here: www.innovie.com . You can see in the front page of this site. There are many other sites you can see from the Gallery of silverlight.net as well!

!aDraw - the Silverlight ones don't run

@Hoc:

I don't see how you can expect Flash to display an image that says "Flash Not Installed" if the Flash plugin is not installed.

Showing an alternate image instead of the missing Flash is in the hands of the web desinger/developer. Planning ahead allows you to show alternate content in case of a missing plugin. This is the case for Silverlight as well because I doubt Silverlight has the ability to show an image when the Silverlight plugin is not installed.

Flash is clearly better. It works like a charm in Google Chrome and performs better under CPU load. Just try opening multiple browser windows and start the Flash & Silverlight examples multiple times. Silverlight often has trouble with just 1 window. Flash just keeps on going.

The flash version usually seems faster and also when scaling images the flash version looks smoother.

Look at the Water effect. In Silverlight the trail becomes longer with the same mouse movements, which this indicates that Silverligth is rendering with noticeable fewer frames per second.

For those confused who the real winner is?

Download ebay desktop and experience

http://desktop.ebay.com/

@Richard Monson-Haefel
What about your company product Curl ?
Can the trees be developed faster than these Flex, SL apps with same quality of animation and images with effects using Curl? If you will submit the Curl versions of these we can better compare ;)

Seems like there's some MS hate going on here in the comments. For example, I am not sure why knowing the eBay desktop is written in Adobe AIR determines a clear winner. Just because eBay uses AIR, I am supposed to believe that it's clearly better?

I have noticed that Silverlight has serious performance issues when more than one instance of the SilverLight control is running, even if they are running in separate processes, whereas Flash doesn't seem to suffer the same problem.

An earlier post claimed that Silverlight lags behind in "Expressive stuff like drop shadows, glows, blend layers, bitmap caching, etc." Although this was true in the beginning, even Silverlight 2 has these features. I can't claim to be able to do a fair head to head comparison because I don't know either technology well, but for a sample of Silverlight effects, checkout this older blog post from Tim Rule: http://blogs.msdn.com/timrule/archive/2008/04/29/innerglow-effect-for-silverlight-2-beta-1.aspx