Appium

Appium is an open-source, cross-platform test automation framework for mobile applications. It enables automated testing of native, hybrid, and mobile web apps on iOS, Android, and Windows devices. Appium drives devices using the WebDriver protocol, allowing tests written against a common API to run across multiple platforms with little or no modification.

The project consists of a Node.js server that exposes a WebDriver API and client libraries in several languages (Java, Python, JavaScript, Ruby, C#, PHP, and others). When a test issues commands, the Appium server translates them into platform-specific automation frameworks: UIAutomator2 on Android, XCUITest on iOS, and WinAppDriver for Windows apps. For hybrid and mobile web apps, Appium handles context switching between native code and web views, using the appropriate browser driver (for example ChromeDriver for Android webviews and SafariDriver for iOS webviews).

Key advantages include its cross-platform reach, no need to modify the app's source code, and a single test suite written against the WebDriver standard. To run tests locally, developers must install platform tools such as Xcode on macOS for iOS, Android SDK for Android, and the Windows Appium setup for Windows apps. Appium is licensed under the Apache License 2.0.

Since its inception, Appium has become a widely used tool in QA and DevOps, with a large ecosystem of language bindings, integration with CI pipelines, and availability via cloud device farms and test services. The project is maintained by an active community and comprehensive documentation.