Apple's 'iPhone software roadmap' invitation in 2008

There was little doubting what this invitation and subsequent event were all about. The event, which took place the first week of March, played host to the unveiling of the iPhone software development kit. Apple CEO Steve Jobs had promised such a thing in an open letter to the Apple community on Apple's Web site in mid-October of 2007.

The event also brought the introduction of the App Store, Apple's software marketplace, which is currently on the cusp of surpassing 25 billion downloads.