Mr. Jobs—after months of criticism from Adobe and software developers for his company's decision to ban Flash from iPhones, iPods and iPads— Thursday took the unusual step of posting a lengthy essay on Apple's Web site criticizing Adobe's software as a flawed throwback to a time before smartphones caught the fancy of consumers.
"Flash was created during the PC era—for PCs and mice," Mr. Jobs wrote in an essay totaling more than 1,600 words. "The mobile era is about low power devices, touch interfaces and open Web standards—all areas where Flash falls short."
Adobe CEO Shantanu Narayen fired back in an interview with The Wall Street Journal, disputing Mr. Jobs's assertions about shortcomings in Flash. That is a "smoke screen," he argued, for Apple's plan to keep its own lock over software development for its mobile devices. "It's clear that it has nothing to do with technology," he said.
The tough rhetoric underscores the huge stakes in setting key technical standards for the mobile Internet, a process that could affect the fortunes of device makers, programmers, media companies and advertisers.
Apple, a PC pioneer whose influence in that market waned, has won new power in the mobile world because of the success of the iPhone and the App Store created to supply software for it.
Analysts and industry executives don't expect Mr. Jobs to readily share that power with other standard-setters such as Adobe. "They are trying to control their ecosystem," said Jeffrey Hammond, an analyst at Forrester Research, of Apple. "It's all about control."
Mr. Jobs, through a spokeswoman, declined a request for an interview to elaborate on his essay and the reason for releasing it now.
Media companies and advertisers have privately expressed frustration about Apple's stance toward Flash because their online video and other Web content incorporates Flash. Adobe, meanwhile, has said it will try to work closely with Google Inc. to popularize Flash on phones using Google's Android system.
Flash is the most popular video format on the Web, and is also used for animation and advertising. It has been slower to take hold in cellphones, but Adobe has recently introduced new versions aimed at mobile devices.
Instead of Flash, Apple is supporting Web sites that use an emerging standard called HTML 5, which is being developed by a consortium that it is a part of alongside Google. But some Web developers say HTML 5 isn't yet ready to be used for anything besides trials.
Apple's anti-Flash policy is not new, but attained greater prominence after the iPad was first publicly demonstrated in January. With a small device like the iPhone, people expected a truncated version of the Web, but with the iPad, people had expected to be able to watch video on the device's big Web browser, said Ben Bajarin, an analyst at Creative Strategies, a research and consulting firm.
Dave Wolf, vice president of strategy at Cynergy Systems Inc., a Washington, D.C., design firm, calls Apple's no-Flash policy "a pain." Mr. Wolf had planned to build apps for clients using the new Adobe software.
Developers are "caught in the middle," agreed David Clarke, founder of BGT Partners, a Web design firm in Miami.
The essay is a rare but not unprecedented move for Mr. Jobs. Three years ago he published a statement urging the music industry to let Apple sell music without anticopying software.
The debate has divided the media and technology industries. Adobe supporters created a Facebook page called "I'm with Adobe" that has nearly 11,000 members while others have sided with Apple.
Mr. Hammond of Forrester said many points raised by Mr. Jobs are just wrong. But other analysts disagreed. "I think Jobs summarized all the frustrations he's had," said Rick Doherty, an analyst with consulting firm Envisioneering Group. "I'd be really surprised if Adobe can challenge his arguments because they're predominantly true."
Mr. Jobs argues in his letter that Flash hasn't worked well on cellphones, shortens their battery life, adds security problems and doesn't support touch interfaces. He said Adobe's effort to use Flash to create apps for Apple's devices could cause problems if Adobe were slow to add support for Apple enhancements.
Adobe's Mr. Narayen said developers and consumers benefit from Adobe's multi-platform approach, which could ultimately make apps for iPhones work on other devices. "It doesn't benefit Apple and that's why you see this reaction," he said.