iOS 2 was released on July 11, 2008. It was announced on March 6, 2008, and launched alongside the iPhone 3G. This version introduced the App Store and a software development kit (SDK) for third-party app development, among other features.
If the question is about iOS 2's original release date, that is the information. If the question refers to a version "iOS 2" in the current context, it is important to note that Apple now names their system much later in numbering, with the latest being iOS 26 as of September 15, 2025.
Please clarify if information about the original iOS 2 or something else related to "iOS 2" is needed.