Apple has changed the terms of its licence to prevent the use of anything other than its approved software development kit to create applications for the iPhone, iPad and iPod Touch. In revealing its clause, Apple poses a problem for Adobe, which is poised to announce a tool in the next release of its software to allow applications authored in Flash to run on the iPhone.

Apple has excluded Flash from its iPhone operating system, ostensibly for performance reasons although it also ensures that Apple can maintain control of the application market for its devices.

Adobe had planned to provide a packager tool to allow developers to create applications in Flash that could be cross-compiled to run as natively using ARM byte code in the Apple environment.

Following the announcement of the latest release of the Apple iPhone operating system, the wording of the developer programme licence agreement now explicitly states that “only code written in C, C++ and Objective-C may compile and directly link” to its application programming interfaces and that applications that link “through an intermediary translation or compatibility layer or tool are prohibited”. That includes not only the Adobe iPhone packager but other third-party frameworks.

Adobe has acknowledged the risk in a regulatory filing, saying “to the extent new releases of operating systems or other third-party products, platforms or devices, such as the Apple iPhone or iPad, make it more difficult for our products to perform, and our customers are persuaded to use alternative technologies, our business could be harmed.”

The company is down playing the significance, with Adobe chief technology officer Kevin Lynch saying “the ability to package an application for the iPhone or iPad is one feature in one product” of its new Creative Suite of software. “We intend to still deliver this capability in CS5 and it is up to Apple whether they choose to allow or disallow applications as their rules shift over time.”

Adobe also points out that the ability to deliver applications to multiple screens extends beyond the Apple world, saying “This year we will see a wide range of excellent smartphones, tablets, smartbooks, televisions and more coming to market”. That of course includes the Google Android platform.

Nevertheless, the iPhone and iPad have been category defining products and the continuing conflict between Apple and Adobe limits the ability for developers to create applications once that will run on a range of devices and displays.

Time will tell whether Apple will be able to maintain its position and prevent the large community of Flash developers from using Adobe tools to create applications for its platform.

Either way, it demonstrates the dangers of being tied to proprietary programming environments that are ultimately subject to commercial considerations.

One effect of the lack of Flash support on the Apple iPhone platform has been to promote the adoption of HTML5 to deliver standards-based video that will play across a wide range of devices.