The current stable version, iOS 17, was released to the public on September 18, 2023. Major versions of iOS are released annually. These mobile apps have collectively been downloaded more than 130 billion times. As of December 2023, Apple's App Store contains more than 3.8 million iOS applications. Since its launch, iOS has been extended to support other Apple devices such as the iPod Touch (September 2007) and the iPad (introduced: January 2010 availability: April 2010). It is the basis for three other operating systems made by Apple: iPadOS, tvOS, and watchOS. It is the world's second-most widely installed mobile operating system, after Android.

It is the operating system that powers many of the company's mobile devices, including the iPhone the term also includes the system software for iPads (predating iPadOS, which was introduced in 2019) as well as on the iPod Touch devices (which were discontinued in mid-2022).

It was unveiled in January 2007 for the first-generation iPhone, launched in June 2007.Īlthough some parts of iOS are open source under the Apple Public Source License and other licenses, iOS is an Apple proprietary software.

IOS (formerly iPhone OS) is a mobile operating system based on macOS and on components of the Mach microkernel and FreeBSD, a Unix-like operating system, developed by Apple Inc. Proprietary software except for open-source components