Unveiling its iPhone 4.0 SDK (software development kit) beta on Thursday, Apple has now made official its intentions of keeping Flash apps from running on the iPhone – changing the terms of its iPhone Developer Program license agreement in such a way that it forbid cross compilers, via which developers write iPhone apps using languages other than Apple’s Objective-C.

The notable cross compilers – tools that offer developers the flexibility to code in different languages and port their software into native iPhone apps – include Adobe’s Packager for iPhone; Adobe’s forthcoming Creative Suite 5; and others made by smaller companies like Appcelerator.

The changed terms of the agreement – which is required for accessing tools for developing apps for the iPhone, iPod Touch and iPad – are a clear indication that Apple has further tightened its grip over the iPhone.

The new developers’ agreement is the first-ever attempt to disallow apps developed using “intermediary translation” tools, like those made by Adobe, from running natively on the various Apple brand mobile devices.

Commenting on the new iPhone developer agreement, NPD analyst Ross Rubin said: “It seems like it will be difficult for Adobe to get around this restriction. Apple wants to ensure developers use the technologies exposed in its tools and wants to avoid being an assimilated platform. It extends the Flash ban and says Apple is willing to risk doing without certain content rather than ceding control to Adobe.”