The iPhone operating system, known as OS X iPhone is developed by Apple Inc. specially for this type of phones, used also on the iPod Touch. Just like the Mac OS X does, this operating system uses the Darwin foundation, which is compose by code derived from Next Step, BSD and some other free software projects. That’s why, every iPhone and iPod Touch is compatible with the Single UNIX Specifications version three and Posix UNIX applications and utilities. It takes less than 240 MB of the device’s memory storage and it is based on the concept of direct manipulations.
A home screen, rendered by Spring Board, with application images, and a platform at the lower side of the screen, indicating the icons for the applications the user access more often, is presented when the phone is turned on or anytime the home button is pushed. The display has a status bar to the opposite side of the top to display data, like time, battery level, signal intensity. The rest of the display is consecrated to the used  application. There is no concept of opening or closing  applications, only starting an application from the home display, and leaving the application to return back. It is possible to force-out an application to quit by pressing the power button until the “slide to power off” button appears, and then pressing the home button down. Although some multi-tasking is permitted it is not noticeable . However, it is restriction to applications released only by Apple. Third-party applications are ended when left, but with the 3.0 software upgrade, notices will be able to be downloaded from Apple’s sites to the iPhone or iPod Touch. Many another of the admitted applications were created to work together, making the possibility of the sharing or cross extension of data from one to another. For example, a number  of phone can be selected  into an application and saved as a contact into another or dialed.
On October 17, 2007, into an announce posted to Apple’s Hot News, Steve Jobs said that a software development kit, also known as SDK, would be released for3rd part programmers . The SDK was published on March 6, 2008, and let the developers to create  applications for the iPhone OS X, and also test them in a simulator, which looks exactly like the iPhone. Still, loading an application into the simulator is accepted only  after  you pay a fee for the iPhone Developer Program.
Programmers  are permitted to set any cost for their software and release them for distribution on the Apple Store, of which they will get a 70% pay. Alternate, they may choose to release the apps as free sources and don’t need to pay any other cost.
Since it was released, there has been some disputes involving the refund policy in the published print of the developer agreement with Apple Inc. In accord with the idea that programmers must agree to, if someone buys an app from the app store, 30% of the cost goes to Apple, and 70% to the coder. If a refund is gave back to the buyer, only if Apple agrees, the 30% is returned to the buyer from Apple, and 70% from the programmer. Apple Inc. can get another 30% of the cost from the programmer to cover their loss.
Apple didn’t announced any projects to enable Java to work on the iPhone. Sun Microsystems announced that they will release a Java Virtual Machine, known as JVM for iPhone operating system, founded on the Java Platform, Micro Edition. This will help the Java programs to run on iPhone and iPod Touch.
Right after this announcement, programmers which were familiar with the SDK’s terms of agreement thought that by not allowing third-party programs to run in the background, like to be able to answer if your phone calls and the application to still work, letting  a program to download the code from another program, or allowing an application to interact with a third-party application, like JVM with Safari, could block the development of the JVM without the Apple’s pattern.
It is more than sure that Java running on the iPhone is beyond the boundary  of the iPhone SDK Agreement.
The iPhone OS don’t support Adobe Flash, and Flash movies can’t be viewed on web pages. Even thought Adobe released 2 versions of this software, Apple views incomplete and not as suitable for the iPhone. Apple’s argumentation to the public so far has been that Flash would be too difficult to handle or use especially because of size or weight for the iPhone, while Flash Lite, the second version released, would not allow a suitable feel for users.