Adobe is king of many realms. From the de facto web development software, Dreamweaver, to its once ubiquitous presence in the form of Adobe Flash web apps, Flash players, Flash games and Flash websites (not to mention Adobe PDFs), Adobe’s stranglehold on the web development world has been nearly as monopolistic as Microsoft’s on desktop productivity. But Adobe’s prominence in the future of web development now faces some serious challenges. The first, of course, was the iPhone, which, along with the vast majority of smartphone platforms, doesn’t support even a lick of Adobe Flash. This caused many web developers to gravitate away from Flash elements, or to develop mobile-friendly websites or dedicated apps for their web services. The effect on the web has been pervasive, with many web dev hipsters proclaiming Flash websites passГ©.

Of course, that’s far from the truth—for now, and the near future. Google Chrome, for example, has Flash support built-in—and many smartphone platforms, such as Android and Symbian, have been making strides towards supporting Flash. But the challenge of working around a proprietary web plugin has sent many developers looking for more universal alternatives.

Enter HTML5. HTML5, which is maintained by the W3C working group (rather than a for-profit software company) has proven friendlier to a web with many roads leading to it—from tablets and smartphones to netbooks and web-enabled Blu-ray players. Simply put, HTML5 has been shouldering some of the dynamic and interactive workload that browsers without Flash support can’t. This has many large web communities and web apps re-evaluating whether it’s even worthwhile to use Adobe Flash anymore.

Case in point: Google is offering a sans-Flash version of YouTube to brave beta testers. For years, YouTube has been dabbling in HTML5 video playback, and it currently already has an HTML5 embeddable player that’s iPhone/iPad friendly. But now, they are ramping up their efforts to make a completely Adobe Flash-free web video experience. You can try out the new YouTube.com HTML5 video player on your web browser by visiting http://www.youtube.com/html5 and opting in to the HTML5 trial.

The HTML5 trial allows you to watch YouTube videos in Firefox 4, Google Chrome, Opera 10.6+, Apple Safari and Internet Explorer 9 without having Adobe Flash installed on your computer.

For many users, that’s a relief. Aside from consuming hard disk space and resources, Flash plays a role in displaying the most obnoxious ads and introducing certain security vulnerabilities.

There are some limitations as of the writing of this article, however. Fullscreen support is only partially implanted. For example, it only fills up the browser—you’ll then have to activate the fullscreen mode in your browser to get true fullscreen.

Also, video annotations are not currently supported in the YouTube HTML5 video player. Nor are videos with ads. If you try to play a video with ads in it, you’ll be automatically switched over to the Flash player (so either use Chrome or keep the Adobe Flash plug-in installed).

You can join or leave the HTML5 trial at will. Give it a shot and see how one of the web’s most popular destinations feels without Adobe Flash. You just may be glimpsing into the future.