The days when web pages were static collections of text and graphics are long past.
However, as the web matures, there's fierce competition over which technology will propel it into a medium for rich, interactive applications.
On one side of the battle lines is the original web-page-description technology: HTML, or HyperText Markup Language. Over the years, its abilities were augmented first with JavaScript, a basic programming language, and later with Ajax.
On the other side is Adobe's Flash, which began as a method for graphic animations. It's grown into a much more powerful programming foundation over the years and has been recently joined by a competitor: Microsoft's Silverlight.
All these technologies are advancing rapidly as internet start-ups and giants, such as Google, race to transform PC software into services available on the internet. These so-called 'rich internet applications' rarely match the performance and features of PC-based applications, at least today, but online applications can benefit from sharing, reliability and access from multiple devices.
Consumers typically need not worry much about the programming plumbing beneath their online applications. However, suppose you're the person on the hook for your company's online expense-reporting tool or a start-up planning to build an online music mixer for anyone on the internet. You'll have to place a bet on which technology is best and which programmers to hire or train.
Few expect the competition to have a winner any time soon.
"You'll continue to see a high degree of flux for probably the next several years," said Kevin Hoyt, an Adobe technology evangelist for rich internet applications.
People in the computer industry like to talk about competition, which, indeed, often does keep companies from growing complacent. However, it's also convenient when some foundational technology — Windows, JPEG and USB for example — dominates to the point where most engineers need not worry much about the messy chaos of multiple choices.
The HTML camp
The HTML side of the battle has its roots in industry standards and in the task of displaying information. That's both good and bad.
Industry standards can attract broad adoption, but they're typically slow to arrive. And although both JavaScript and HTML are standards, differences in how they're implemented in different browsers — and even different versions of the same browser — force programmers to accommodate all the possibilities.
Unlike during the browser wars of the 1990s, however, there's more convergence than divergence these days. Even the upcoming version 8 of the dominant browser, Microsoft's Internet Explorer, will ship in a standards-compliant mode by default.
HTML also can't be beat for pervasiveness, which is one reason why Kevin Henrikson, director of engineering at Zimbra, is a fan. Zimbra, which provides online email and other applications, was an early Ajax adopter and in 2007 was acquired by internet giant Yahoo.
"Even if I were starting from scratch today, I still think I'd bet on JavaScript and Ajax... It's going to be hard to stop the massive momentum we have," Henrikson said. "Flash is seeing a pretty aggressive growth cycle now, [but] I still think JavaScript is going to be [used in] 10 times the number of Flash apps that launch."
Microsoft sees things differently, believing that programmers are best off ditching HTML and JavaScript as soon as web applications start getting rich.
"It's amazing what people have done with HTML, which was never intended to do rich internet applications. And Flash was originally created for lightweight animation — literally for Mickey Mouse on the web," said Brad Becker, who as group product manager for rich client platforms at Microsoft helps oversee Silverlight. "But these technologies were designed for something else, and people are really hacking them to do more."
Overhauling HTML and JavaScript
However, big changes, which may rectify HTML's shortfalls, are on the way.
One idea that's established, but still has a way to go, is more sophisticated data storage that can let applications keep local copies of data or documents for a long time. One important use of this technology is letting people use their web applications even when offline.
Other big HTML changes include Canvas, to let browsers create customised graphical elements, such as charts, on the fly, based on programming instructions rather than just downloading pre-fabricated elements from a website; Web Workers, to let browsers perform computationally intense background tasks without disturbing the browser interface; and Scalable Vector Graphics (SVG), an existing standard, which, if adopted more widely, could encroach on some Flash abilities.
Further out on the horizon are audio and video tags for HTML that would let browsers play media with no extra plug-ins needed. If the industry manages to wade through the technological and intellectual-property difficulties involved, it could erode one of main advantages of Flash and Silverlight.
"If you put it all together, that lends itself to Ajax being a very powerful, capable rich-internet-application technology," said Adobe's Hoyt.
The Google guns
Google is perhaps the biggest gun backing HTML, JavaScript and Ajax. Its Gmail and Google Maps sites woke many up to the possibilities, and the company followed up with Google Docs for online word processing, spreadsheets and presentations.
But just because Google is doing something doesn't mean it's the right way, Becker said. "If you look at Google Apps, they're doing great things, but how many shops out there have the Ajax chops that Google does?"
Google is trying to hard to give new ammunition to the HTML camp, in part by…
