In 2000 I worked for WebOS.com (site still exists, but you wont find a working product), developing a pure JS desktop environment much like the linked page. The development API was loosely based on Swing and sported a full SDK. There was no Flash involved at all, it was entirely DOM based and employed numerous techniques to improve speed. We even had a system for doing JSONp data communication, back before anyone even know what JSONp was.
Once the thing loaded it was wicked fast, as fast as any native interface, and this was back when IE6 was the top dog and JS engines were horribly unoptimized. If the code still worked it would probably scream in Chrome.
Technological limitations were not the problem, usefulness was. We completed the product and discovered that nobody had any idea what to do with it or a way to monetize it. We considered selling it as a foundation for other companies to build systems on (medical would have loved it), but we had no buyers. Then the dot.com crash happened and it all just went away.
Once the thing loaded it was wicked fast, as fast as any native interface, and this was back when IE6 was the top dog and JS engines were horribly unoptimized. If the code still worked it would probably scream in Chrome.
Technological limitations were not the problem, usefulness was. We completed the product and discovered that nobody had any idea what to do with it or a way to monetize it. We considered selling it as a foundation for other companies to build systems on (medical would have loved it), but we had no buyers. Then the dot.com crash happened and it all just went away.