By Alistair Fairweather

Something momentous happened on Wednesday — something most people will never even hear about. Adobe, a software firm, announced that it is ceasing development on the mobile version of its Flash platform.

That probably doesn’t sound very momentous, but let’s look closely at the implications. Flash has been a dominant platform on the Web for more than a decade. It is installed on 99% of computers that use the Internet. No one else has anywhere near that kind of market presence — not even Microsoft. Now, after years of struggling for acceptance in the mobile market, Adobe has accepted defeat.

Most Web users are unaware of Flash unless there’s a problem with it, but chances are you’ve used it several times today already. Flash plays videos, animates banner adverts and online greeting cards. Flash runs games and uploads files smoothly. Some adventurous types (such as Ster Kinekor) have even built entire websites using the platform.

But Adobe has never been able to crack the mobile market, thanks partly to Apple. When the first iPhone came out in 2007 people assumed that the lack of support for Flash was an oversight that would soon be corrected.

By early 2010 it became clear that the omission was intentional. In an open letter, Steve Jobs made Apple’s position clear: Flash was bloated, proprietary and unreliable. In short, it wasn’t coming anywhere near the iPhone or iPad.

At the time the criticisms seemed self-serving: Apple just didn’t want Adobe horning in on its neat little ecosystem. But, like many of Jobs’s decisions, it looks increasingly prescient. Despite Android and Blackberry adopting mobile Flash, Adobe has been forced to abandon it. It will, instead, focus on the new HTML5 standard.

But the threat to Flash’s future runs deeper still. The big browser players Mozilla (who make Firefox), Google (Chrome), Apple (Safari) and Microsoft (Internet Explorer) are all moving rapidly towards adopting HTML5, which takes over a lot of Flash’s bread and butter duties like playing videos and animation.

So why would they callously discard an old compatriot, particularly one that works so well? Simple: none of them want their products to be beholden to a proprietary platform like Flash. HTML5, by contrast, is a public standard with no owner and no royalty implications.

As long as Flash is owned by one company it is doomed to decline. Given the enormous number of people with skills in Flash, and its momentum in the market, it will be a significant force for at least another decade. But this is the beginning of the end of its dominance.

If I were Adobe I would seize this opportunity to “open source” the platform. By releasing its source code into the wild, it has a hope of keeping it alive in the long term. Adobe has made billions of dollars from Flash over the years. Now it needs to choose which is more important: short term profits or long term sustainability. Let’s hope it chooses the latter.