Apple chief executive Steve Jobs has written an open letter outlining his reasons for not allowing Flash on his firm's mobile devices, in the latest instalment of the fallout between Apple and Adobe.
The letter, entitled Thoughts on Flash, comes after Mike Chambers, principal product manager for Flash at Adobe, announced that the firm is to stop focusing on the iPhone and shift its attention to Google's Android platform.
Jobs has responded by dismissing Flash as "no longer necessary to watch video or consume any kind of web content", saying that his main reasons for refusing to let Flash on Apple devices are "technology issues".
His concern is that Flash forces developers to create apps in Flash, and that they therefore become dependent on Adobe for enhancements and new features.
"We know from painful experience that letting a third-party layer of software come between the platform and the developer ultimately results in sub-standard apps, and hinders the enhancement and progress of the platform," said Jobs.
"We cannot be at the mercy of a third party deciding if and when they will make our enhancements available to our developers."
"While Adobe's Flash products are widely available, this does not mean they are open, since they are controlled entirely by Adobe and available only from Adobe. By almost any definition, Flash is a closed system," he said.
Jobs also dismissed Adobe's claim that not running Flash denies users a full web experience, arguing that new video formats are making this argument irrelevant.
"What [Adobe] doesn't say is that almost all video is available in H.264 and viewable on iPhones, iPods and iPads. YouTube, with an estimated 40 per cent of the web's video, shines in an app bundled on all Apple mobile devices," he wrote.
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