Apple's annual developer conference in San Francisco.
iPhone OS 4 Becomes iOS 4, Available June 21 for Free
iOS 4 has been declared Golden Master Candidate and will be publicly released on June 21st. It will be a free upgrade for existing iPhone and iPod touch owners, though depending on the age of your device not all features many be available. This is the first time that a major OS update has been free for iPod touch owners.