Apple has announced the 4th release of mobile operating system that is known as iOS 4 from iPhone OS 4. The iOS 4 Gold Master Candidate with the SDK is available for registered developers whereas the iOS 4 update will be released to all iPhone and iPod Touch users in free on 21 June, 2010 and iPad will get that in fall 2010.
Several beta versions of the iOS 4 have been released before as first iPhone OS 4 Developer Preview and beta 2 was revealed in April 2010, whereas beta 3 and beta 4 were released in May 2010.
The iOS 4 includes 100 new features and 1500 APIs as some of iOS 4 features are multi-tasking, better email, Bing integration with Safari, unified inbox, apps folders, iBooks, Retina display, improved camera and photo apps etc.
The Enterprise iOS 4 version will contain support for MS Exchange Server 2010, SSL VPN, enhanced Mail app functionality, and data protection.
The iOS 4 also will work for iPhone 4, 3GS, and 3G and iPod Touch excluding the first generation iPod Touch. The iOS 4 all features are not compatible for all devices, as multitasking feature only works on iPhone 4 and iPhone 3GS.
Developers can download iOS 4 GM Candidate so it could be possible that final version will be release later.
iPhone Dev site down, Golden Master coming shortly.