In that sense, webOS applications are like native applications. But they differ by running in the WebKit engine instead of interacting directly with an underlying OS.
"Your application is running as though it were a kind of series of dynamic Web pages in an embedded browser," says Pandora's Conrad. "It's not compiled into 'non-Web code.' It executes within a true Web environment."
Multitasking to the max
Multitasking -- being able to run several applications at once on a mobile device -- isn't unique. RIM's BlackBerry OS supports it, as does Microsoft's Windows Mobile. Even Apple's iPhone OS supports it, though Apple restricts third-party use of this capability.
But multitasking often is limited and hard to exploit in conventional platforms, according to Pivotal's McFarland. "If you're composing an e-mail on the iPhone, you can't check other e-mails in the same thread, or check a Web site to add a link to the e-mail, or copy-and-paste something," McFarland says. "You can't do these kinds of things on most mobile platforms."
By contrast, "webOS has fully embraced the notion of applications running at the same time, as PCs do," Sepulveda says. "You can now write applications that are more complex."
That ability raises the potential for problems, however. Apple restricts multitasking on the iPhone in part to prevent applications from interfering with each other or hogging limited memory, battery and CPU resources. The webOS developers wouldn't go into details, but they say Palm has addressed those issues.
"I think you always run the risk of a programmer running amuck," says Eric Marthinsen, a partner at Agile Commerce, a Lexington, Mass., development shop that specializes in building custom, Web-based systems for start-ups. Agile has been working with webOS and Mojo since early January. "But the way Palm has approached multitasking is very smart. It really mitigates that risk."