Apple has introduced the sixth version of its iPhone SDK, saying it includes support for the ‘latest iPhone software’.

The new release also requires that Mac OS X 10.5.3 be installed, the company said, revealing the SDK won’t work with previous operating systems.

The  1.19GB download is available from the iPhone Dev Center and includes a complete set of tools, compilers, frameworks, and documentation, including an iPhone Simulator for testing. 

Release notes detailing the new version are available here. 

One new feature within the recent Mac OS X 10.5.3 upgrade saw better support for Google. The Address Book application in Mac OS X 10.5.3 now lets iPhone users sync their Address Book with Google Contacts. To try it, go to the Address Book menu, choose Preferences, and then check Synchronize with Google. It’ll ask for your Google account and password, then automatically update your contacts every time you sync your iPhone, reveals Google.