Operating system

Lore & Background

The first computers in the late 1940s and 1950s were directly programmed with plugboards or machine code inputted on punch cards, without programming languages or operating systems. By the early 1960s, mainframes had rudimentary operating systems such as the Fortran Monitor System (FMS) and IBSYS.

Reader's Guide

Operating systems are fundamental to modern computing, serving as the layer of software that manages a computer's resources for its users and their applications. They allocate resources between different applications, deciding when they will receive CPU time or space in memory, and isolate applications from each other to protect them from errors and security vulnerabilities. Operating systems provide an interface that abstracts hardware details, making things easier for programmers, and offer common services such as access to network and disk devices, enabling applications to run on different hardware without being rewritten. Specialized classes exist, including embedded and real-time systems, security-focused operating systems, and those with low or high system requirements. As of November 2025, Android is the most popular operating system with a 38% market share, followed by Microsoft Windows at 33%, iOS and iPadOS at 15%, macOS at 4%, and Linux at 1%. Linux distributions are dominant in the server and supercomputing sectors.

Did You Know?

• Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources.
• For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although application code is usually executed directly by th
• Some operating systems require installation or may come pre-installed with purchased computers (OEM-installation), whereas others may run directly from media (i.e. live CD) or flash memory (i.e. a LiveUSB from a USB stic
• A hypervisor is not an operating system; it is a virtualization layer that runs virtual machines.

From Camera Prototypes to a Mobile Empire

Android Inc. Rubin, who had previously created the T-Mobile Sidekick at Danger Inc., initially aimed to build an operating system for digital cameras under a project called FotoFrame. The name "Android" stuck simply because Rubin already owned the android.com domain. After constructing an internal prototype called the "Fadden demo" using a custom JavaScript front-end, the startup failed to attract investors. Perlman declined any equity stake, saying he simply believed in the project.

The Open-Core Paradox

At its foundation, Android rests on the Android Open Source Project, a free and open-source codebase primarily licensed under the Apache License, originally designed for smartphones. Yet the vast majority of consumer devices do not run this pure open-source version. Instead, they ship with Google's proprietary open-core build, which layers closed-source software atop the AOSP foundation. Most prominently, this includes Google Mobile Services—a bundle containing Chrome, the Google Play digital distribution platform, and the Play Services development framework. Firebase Cloud Messaging, used for push notifications, is also recommended for developers. A critical distinction exists between the code and the brand: while AOSP remains freely available, the "Android" name and logo are registered trademarks of Google, which restricts their use on uncertified products. This creates a layered ecosystem where vendor-customized interfaces like Samsung's One UI coexist alongside community-developed alternatives such as LineageOS and Amazon's Fire OS. The source code has also been adapted for televisions, wearables, in-car systems, virtual reality headsets, and even PCs and micro consoles, demonstrating how a single codebase can span an extraordinary range of hardware form factors.

Unprecedented Global Reach

It has been the most-used smartphone operating system worldwide since 2011, and its installed base remains the largest of any operating system in existence. Software on Android is packaged in the APK format and typically distributed through a proprietary application store, though the ecosystem also accommodates a wide array of alternative channels. Beyond Google's own Play Store, users can access apps through vendor-specific platforms like the Samsung Galaxy Store and Huawei AppGallery, as well as third-party services including Aptoide, Cafe Bazaar, GetJar, and the open-source F-Droid repository. Amazon maintains its own Appstore for Fire OS devices. This multi-channel distribution model, combined with the sheer scale of the user base, has made Android a dominant force in consumer technology, with over three billion monthly active users relying on it daily.

Forging Alliances and Surviving the iPhone Shock

The group's stated mission was to develop what it called "the first truly open and comprehensive platform for mobile devices." Within a year, the alliance faced two rival open-source initiatives: the Symbian Foundation and the LiMo Foundation, the latter also pursuing a Linux-based mobile OS. The project's early prototype bore a striking resemblance to a BlackBerry, featuring a physical QWERTY keyboard and no touchscreen.