The US government has finally taken notice of Apple’s attempts to block its competitors with all possible means and tools. The US Federal Trade Commission and the US Department of Justice are likely to start antitrust proceedings against Apple for anti-competitive practices.

The antitrust inquiry focuses on Apple’s changes to its iPhone developer agreement which is enclosed in the upcoming iPhone OS 4 software upgrade. That addition specifically bans the development of applications using “an intermediary translation or compatibility layer”, which doesn’t allow the porting of software originally written for Adobe’s Flash, Sun’s Java or Microsoft’s Silverlight/Mono to the iPhone OS.

In general, it is quite a blow but focused not on iPhone and iPad developers who have always enjoyed extensive and quality care from Apple’s side. This is a direct attack on Adobe and its allies namely Google. The change resulted in Adobe giving up a recently released software Creative Suite 5 intended for iPhone developers to port Flash applications to the iPhone OS, which is according to new Apple’s rules a violation of the latest developer agreement.

Now developers are forced to choose between creating apps that can run only on Apple gadgets like iPod, iPhone and iPad or come up with platform neutral apps, which can be used in a variety of operating systems environments, such as those from rivals Google, Microsoft and RIM.

It’s quite ironic that having filed a suit against HTC several weeks ago, the company itself has become an object of regulators’ genuine interest. Though the Cupertino company can lull itself that an inquiry does not mean that any action will necessarily be taken, as usually it takes regulators months to come to some agreement and, no doubt, Apple has some parties lobbying its interests.