Ask YC: Do you think Rich Internet Applications (Adobe FLEX, MS Silverlight) are going to take off?

To me, a killer app is usually a single product that creates such a buzz around a new or previously underused technology or concept that causes a sudden almost universal take up by both users and developers and causes long-reaching paradigm shifts.

Google Suggest did it with Ajax, Del.icio.us did it with tags, YouTube did it to online video, Wikipedia for wikis or even the web for the Internet. Not everything becomes popular thanks to 'killer apps' and some innovations are introduced more gradually (such as Flash), but they're somewhat less common and it's generally an uphill struggle before they're adopted.

But the adoption rate of a RIA depends a lot on the platform you use for development. Gmail is a succesful RIA and it uses JavaScript and Flash. The advantage of sticking on to JavaScript/Flash over Sliverlight is that, they are already very popular. If efficiently done JavaScript and Flash can reside side by side delivering a great user experience. So for the time being,because of Silverlight's low adoption rate,a SilverLight only product may not be a great idea.

Regarding Adobe Flex, Flex its nothing more than another development tool for churning out swf files.The end product is plain old Flash. Adobe Flex allows rapid flash development for those unfamiliar with Flash CS3 (CS3's timeline concept doesn't appeal to most developers). Thanks to Adobe's marketing efforts,most people mistakingly think Flex is something RIA exclusive,while its just a development environment that churns out Flash.

SilverLight does solve a lot of headache and reduce learning curve for the traditional .NET developer when it comes to building RIAs.But from a enduser's perspective, it doesn't really bring in any specific advantage. Anything that can be done in SilverLight can be done using Flash or a combination of Flash and JavaScript. I really dont see any enduser specific advantage for using SilverLight, as it is now. Why force users to install new plugins , when the existing infrastructure(JavaScript and flash) can deliver the same user experience?

Adobe AIR is a way to convert your existing Javascript/flash/html based RIA to a desktop app. But this will require the end user to install AIR runtime first(approx 11 MB download). Compared to Mozilla Prism, Adobe AIR is super advanced in the kind of desktop integration it can impart to your web based RIA.A js/flash RIA can leverage on AIR without any tweaks.

In short, use Javascript/HTML as much as possible. Flash when you need to integrate rich media (or functionalities that require realtime user interaction like Chat ) to your js .I wont recommend Silverlight .

Flex allows easy integration of UI concepts like drag-n-drop, neat animations with low cpu usage, integration of streaming media, lowered response times thanks to model caching on the client... and the ease of development should NOT be discounted... Users tend to like an application that exists more than one that doesn't. Ease and speed of development are a huge bonus.

As for the "invonvenience" aspect, interestingly, I've found that the only people who resent Flash in some way are all geeks. The rest of the world is blithely ignorant as to the difference until you explain it to them, and even then they don't care. So, if your primary market is over-opinionated and out-of-date geeks (rather than the more forward thinking ones who are actively writing or learning Flex by now), then definitely don't use Flex.

If, on the other hand, you plan to target the rest of the world, Flex seems like a good bet!

PS: don't use Flex for writing your blog or news site! RIAs are for applications (gmail, gdocs, rescuetime, basecamp), not pure content sites (blogs, slashdot, reddit, NYTimes..).

I said RIA's have their place, they'll succeed a small amount on the desktop where they can be forced upon workers, but on the open internet where they have to compete against web applications, they'll get their butts kicked, as they always have, because they don't force openness.

Allowing the developer the option to hide the code is a fatal flaw, people learn by modifying examples, and that's what makes HTML/JavaScript so unbeatable and viral. When a teenager attempts to learn to program, he'll choose HTML/JavaScript over any RIA platform precisely for that reason, the barrier to entry is much lower. Given the choice to hide their code, most developers will and that creates a barrier to new developers learning the technology.

RIA's aren't new, the idea isn't new, this is what Java was all about, applets, ActiveX components from Microsoft, and Flash from Adobe have all been able to do this for years as well, and they all failed miserably to gain wide adoption. Flash found a niche doing video, but beyond that most developers hate it.

This new batch of RIA's will fail for the same reason, in the end, users don't want them, developers do, to protect their intellectual property. Users don't give a rats ass about a developers intellectual property.

Users are perfectly happy with web apps that use standard controls they understand. RIA's give developers too much freedom to deviate from the normal conventions users are accustomed too. HTML's constraints aren't a weakness to be escaped from, they're a strength that forces you to focus on providing value to the user rather than the mental masturbation of playing with and using non standard widgets that in the end mostly just confuse the average user.

RIA's will always have their place, and it'll always be secondary to HTML/JavaScript, unless an open standard is developed for RIA's that isn't owned by any one company and doesn't require any plugins to run, and doesn't allow developers the ability to hide the code from the users.