Without exception, I find that all my clients know roughly what Flash is. As one client neatly put it “Flash is what you use for whizzy effects on a website”. Any Flash developer will tell you that it can do a great deal more than that, but that's still its primary application. Silverlight is certainly a long way from that sort of brand recognition. Surely Flash will continue its domination — or will it?

Silverlight is Microsoft's answer to Flash. Its market share is a fraction of Flash's (which is close to 100% penetration) but it's growing fast. While it's unlikely to kill Flash altogether, if it gains sufficient momentum it could force some developers back to Windows (as the Silverlight development tools only run on Windows). I can't comment on those tools, but have heard they're very good, and certainly C# is an elegant and appealing language.

It might seem that the question is “why use Silverlight when you can use Flash and benefit from its market dominance?’. Doubtless Adobe and Microsoft will be engaged in a long and bitter fight for technical superiority and user acceptance, but there's actually an underlying trend that's far more significant: standard web technologies such as CSS, HTML and JavaScript are rapidly replacing many of the jobs that were once Flash only. Until recently this has been largely confined to tasks that are relatively trivial in Flash and Silverlight: image galleries and slideshows, widgets, nice little animations in navigation, and so on.

What is becoming clear is that even areas such as 3D graphics, which I had thought would keep Flash relevant for a very long time to come, are likely to become possible in mainstream browsers relatively easily, using not much more than a bit of CSS. Flash video, one of Flash's primary applications (as on YouTube, for example), will be superseded far sooner.

So where does this leave Flash and Silverlight? In a very tight spot, especially since neither has any meaningful presence on the mobile web, and none at all on the iPhone, which is surely the market leader (in a technological sense, at least). Personally, I'm a bit sad about this: I love Flash, and use it extensively. But the trend, I think, is unmistakeable.

In short, Flash and Silverlight may battle it out over the next couple of years, only to drift into the dark night of irrelevance.

Posted: 19 March, 2009