As of my last update in September 2021, there were several popular and effective automation tools for software testing. However, please note that the landscape of software testing tools is continually evolving, so it's recommended to check for the latest options. Here are some of the best automation tools for software testing that were widely used:

Selenium: Selenium is a widely adopted open-source tool for automating web browsers. It supports various programming languages like Java, C#, Python, etc., and allows testers to write test scripts to interact with web applications across different browsers.

Appium: Appium is an open-source mobile application automation tool that supports both Android and iOS platforms. It enables testers to automate mobile app testing using native, hybrid, and mobile web applications.

TestComplete: TestComplete is a powerful commercial automation tool that supports automated testing of web, desktop, and mobile applications. It offers record and playback, as well as scripting capabilities using languages like JavaScript, Python, or VBScript.

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