Apple releases iPhone SDK beta 4

Apple has released the SDK beta 4 for the iPhone. This will be given to the registered developers who are already working on the previous SDKs released by Apple. Slowly but steadily, Apple is going mainstream and creating a buzz with its 3G iPhone and then providing support to third part or external developers. The new SDK that is released has two main features OpenGL ES support and Code signing enforced.
Open Gl ES – The iPhone emulator will now be able to render OpenGL ES in applications, matching the capabilities of the iPhone 2.0 software.
Code signing enforced – iPhone applications will now need to contain a valid certificate (obtained from the restricted, $99, iPhone Developer program) in order to be loaded on actual devices. If a developer does not have a certificate, apps will still run in the simulator but not physical devices.