Tuesday, May 22, 2007

A perspective on Apollo vs Silverlight vs JavaFX vs Flash/Flex

In the last few weeks, quite a few RIA framework announcements and/or rebrandings were announced:

  • Apollo from Adobe, which is a runtime to be able to enable richer RIA applications on your desktop.

  • Silverlight from Microsoft, which is a browser plugin to provide a richer RIA browser experience.

  • JavaFX from Sun, which is also a a runtime to enable richer RIA applications on your desktop.

These three frameworks are all in some way also related to Flash/Flex from Adobe.

In this article, I'll be making a first stab at comparing these four frameworks. It should help you to get some perspective and initial understanding on the differences and the similarities.

The goal of all these frameworks is be able to build Rich Internet Applications more easily and to make the user experience as rich as possible. Currently a lot of this kind of functionality is being built with AJAX (asynchronous Javascript, CSS, DOM manipulation and XML) and Flash/Flex. Manual construction of applications with the four AJAX components is quite a pain, and thus companies are trying to create the silver bullet for easy creation of RIA applications. Creating applications with Flash/Flex is relatively easy and makes the applications really rich, but it is vendor-specific (Adobe). Note that recently Adobe made Flex open source (note that this is not the same as the Flash runtime, which stays closed source). Some of the newly announced frameworks are more open source (JavaFX) than others (Silverlight).

To make the comparison easier, I've created a table that lists different aspects of the frameworks I found interesting to have detailed out, and for each of those aspects, how the four frameworks fit in.






is the code name for a cross-operating system runtime being
developed by Adobe that allows developers to leverage their
existing web development skills (Flash, Flex, HTML, JavaScript,
Ajax) to build and deploy rich Internet applications (RIAs) to the

is] a runtime complementary to the browser, to bring webapps to
the desktop, so richer and more interactive RIAs"

is a cross-browser, cross-platform plug-in for delivering the next
generation of Microsoft .NET–based media experiences and
rich interactive applications for the Web"

Script takes advantage of the Java Runtime Environment's (JRE)
ubiquity across devices and enables creative professionals to
begin building applications based on their current knowledge base.
It also uses Java technology's "write once, run anywhere"
capability to help realize a future where consumers can access
content whenever and wherever on any Java-powered device.”

"[...] is software for creating rich, interactive content
for digital, web, and mobile platforms." “[...] it
provides the tools you need to deliver an engaging user

“[...] it is an application development solution for
creating and delivering cross-platform rich Internet applications
(RIAs) within the enterprise and across the web.” It has a
client-runtime which is based upon the Flash Player.

is Flex different from Flash: “Flex and Flash have
complementary strengths. Flash is the leading authoring tool for
web developers, multimedia professionals, animators, and
videographers who want to create rich interactive content. Flex 2
products enable more application developers to leverage the
powerful Flash runtime to create data-driven RIAs. In addition,
developers can use Flash and Flex Builder together to add rich
interactive elements to a structured, Flex based application.”


public beta in US summer, v1.0 early winter 2007



version CS3

version 2





client-runtime uses Adobe Flash Player 9: 1.1MB.

client-runtime uses Adobe Flash Player 9, 1.1MB.


outside browser

for browser + based upon existing WPF/E (.NET based) platform for
Windows and Mac

language F3+runtime outside browser+java

IDE to build Flash applications with ActionScript.

"The Flex [UI] application framework consists of MXML,
ActionScript 3.0, and the Flex class library. Developers use MXML
to declaratively define the application user interface elements
and use ActionScript for client logic and procedural control.
Developers write MXML and ActionScript source code using the Adobe
Flex Builder™ IDE or a standard text editor."


+ Linux + Mac

browser + Mac browser

+ Linux + Mac

player client-runtime: Windows + linux + mac


(not opensource)



closed, Flex: OSS



Sample Apollo apps: Apollohunter

Open source JavaFX wiki: wiki

Since Silverlight is meant to be running in the browser, it should be seen much more as a competitor to Flash/Flex than to the Adobe and Sun solutions, which are runtimes running outside the browser. Currently Flash/Flex has of course a large installed base already. Silverlight has the advantage it can easily be put on every Windows computer by letting it piggy-back with some automatic Windows update. The Apollo and JavaFX solutions are a very interesting new development where much richer internet applications can be built, because they run outside the browser, thus giving much more freedom to build richer GUIs. Some interesting questions that remain for these runtimes are:
  • Are users willing to wait for 4-6 MB downloads?
  • Are we now again moving away from making the browser the platform? Notice that Mozilla is extending the browser even more via XUL to become one RIA platform. See here for some more info on that.

Finally, here are a few other interesting developments in this area:

  • The Mono project is going to try to port Silverlight to Linux.
  • MS just announced a new Silverlight app Popfly that allows users to create mashups (like Y! Pipes).
  • A lightweight JRE for Java 6 is indeed not a rumor and thus the amount of runtime to download is significantly reduced.
Sources for this article were:
Other Resources
For more detailed information see:

Update 02 June 2007:

  • This week of course Google Gears came out. Here's shortly how it relates to Apollo and Dojo offline. Google is working with Adobe to get it integrated with Apollo. Together with Adobe and Mozilla it is also trying to make Gears an industry standard. Note that you can use each of the 3 components also seperately, you don't need to only use it for writing synchronzation software.
  • Here's another overview of these three and how they relate: Apollo, Silverlight, Gears.
  • Here's a good landscape overview of RIA tools and why Flex could be a good way of building user interfaces, even to Java developers.
  • As John said in the comments, don't forget Java Applets (aren't they extinct? ;-) and XUL.


Anonymous said...

Cool, nice blog post. My website, http://www.riapedia.com showcases a number of applications that people are building with these technologies.

Anonymous said...

If I'm not mistaken, Silverlight is not cross-browser, cross--platform. It might support IE, FF and Safari on Windows and Mac, but I think that's about all (not sure about Opera)

Anonymous said...

Opera is coming soon.. (It's a matter of getting time with the Opera teams)

I think the comparison is Released Version vs Alpha/Beta - keep it in perspective but if it's a pulse check "as of today" then cool, can understand the points being made but think it could go deeper on all flavours.. (ie WPF? that's a valid piece left out and so on).

Rich Web vs Reach Web is more the focal point as well. Apollo has limitations just as much as WPF etc..

Anyway interesting read.

Scott Barnes
Developer Evangelist

Brian Swartzfager said...

Just two things...

1. The Apollo runtime (the software that allows you to run Apollo apps) is indeed a few megabytes in size, but you only have to download it once. The actual Apollo apps themselves that folks make can be quite small (under 100k), so those will be fairly easy to download.

2. For your "Interesting links" for Flex/Flash, use http://try.flex.org/: let's you actually render Flex apps on-the-fly using some simple examples.

Anonymous said...

Forget about Opera. Silverlight will not be crossplatform until it runs on Dillo...on a Vic-20.

Anonymous said...

It should be noted that Linux support for Apollow isn't going to be available in the 1.0 release, according to the Adobe Apollo FAQ.

Anonymous said...

- The JavaFX jar for runtime is ~700K.

- Event though Java apps may take time to download so so all complex Flash apps. And since Flash is such a slow pig, you can watch that percent complete animation crawling towards 100%. You know what I mean!

Anonymous said...

Thanks for creating this table, very handy. I'd been meaning to do one myself as a follow-up to my post that you kindly referenced, but I didn't have time (launching a Startup will do that to you). Now I won't have to.

I thought I should point out that you have Silverlight listed as OSS which it's not. The DLR portion is under the MS Permissive Licence, but otherwise it's a proprietary platform.

Not surprised to hear about the lightweight JRE...I figured it had to be on the way if Sun really wants to join the party, well done for spotting the evidence!

Techie said...

Thanks Seth, amazing how I got that one wrong ;-). Fixed it in the diagram.
Here's another interesting resource BTW: a good landscape overview of RIA tools and why Flex could be a good way of building user interfaces, even to Java developers.

John said...

I like the article but i think there's a bigger battle going on. For the in browser competitors you have ajax(js) vs. Silverlight vs. Flash/flex vs. java applets. In the out of browser category you have XUL (ff3 supporting offline apps with this) vs. WPF vs. Apollo vs JavaFX respectively. After playing with all the different in browser technologies I would have to give the edge to Silverlight though. Regardless I'm very glad there is a lot of competition out there and not just two big companies fighting.

Anonymous said...


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Techie said...

Check bubblemark for example code for all the mentioned frameworks except JavaFX. The Bouncing Balls Animation is an implementation intended for performance comparison of the different frameworks. Additionally source code is available for a Swing (Java) version and a DHTML (Javascript) version.

Techie said...

Apollo has just been renamed to Apollo Integrated Runtime, or AIR for short. And it has gone into beta (was previously released in developer preview).

geekglue said...

Another useful comparison not clearly represented in your very useful table is the development platform. For example, Silverlight can be delivered on the Mac but there are only development tools for Windows. The other thing to note is that the plugin size for Silverlight on OS X is close to 10 MB. Which is enormous when compared to the other options.

Anonymous said...

Calling JavaFX "superalpha" is overly simplified to the point of being unfair. it is riding on the known/stable/reliable Java SE/ME.

Anonymous said...

I think there is one more issue to consider and that is that Silverlight is a Microsoft project. How short does our memory need to be to support silverlight? Does anyone remember Microsoft Foundation Class Library? I cannot believe that a developer would waste their time on it knowing that like so many Microsoft projects it is nothing more than a leverage point and will disappear as soon as it suites them. How does the saying go "embrace and extend" or was that "embrace and detrail"?

Techie said...

Here's a bunch of nice examples of Adobe's AIR (formerly Apollo) only a month after its public beta release: examples
Bubblemark.com (site that has built the same example application in Silverlight, AIR etc) has now implemented a JavaFX version. Performance is disappointing at this moment when using vectors as mentioned here.

PS: I had put JavaFX in as super-alpha because at the point in time I was writing this blogpost, you couldn't even download it.

Techie said...

Check this just released nice hands-on demo of AIR, Silverlight and JavaFX. From the guy who also made the bubblemark benchmarks.

Anonymous said...

I agree that currently Flex/Flash is the best choice over Silverlight and JavaFX. There are more 96% of browser having installed Flash plug-in while Silverlight is still in Beta version. JavaFX is still a vaporware though. Comparing the performance, Flex is more run more smoothly than Silverlight, showing Flex is a more proven technology in RIA area. Flex Builder 3 is also an easy tool for average developers too.

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facildelembrar said...
This comment has been removed by the author.
facildelembrar said...

This article is over 2 years old.
Silverlight is in version 3 now, Flex SDK is in verson 3.4 and JavaFX is in version 1.2.1.
Anyway, for up to date stats of ria platforms there's http://riastats.com. Currently, Silverlight is installed in only 30% of browsers, while Java is present in 70%, and Flash has over 95% market share. Now tracking AJAX is a little more difficult. However, it's worth noting that, according to http://marketshare.hitslink.com , IE6 still has 23% marketshare, so even if you prefer one technology over the other, right now you better stick with flash based solutions for wider audience reach and consistency across platforms.

I've also made a small comparison of some ria technologies for who's interested. Flash, Flex, Actionscript 3 alone, Silverlight using C#, JavaFX, Java and AJAX are covered. You can check the article at http://my.opera.com/facildelembrar
The article is update once in a while with more info.

Leon Victor said...

Good comparison between Apollo, Silverlight, JavaFX, Flash/Flex. Flex/Flash is the best choice in today.