Software development is constantly changing. Therefore, tools and technologies must adapt to this rapid pace of evolution. These changes are designed to reduce delivery times, increase productivity, and improve product quality. Software testing is key to achieving these goals. Automation tools play a central role in the software testing landscape. This article will highlight the five most popular tools that are free for automated software testing.

Selenium is a popular open-source framework for Web application testing. History of Selenium started in 2004 by Jason Huggins as “JavaScriptTestRunner” as an internal tool for ThoughtWorks. It evolved into Selenium 1.0 and Selenium RC, and is currently Selenium WebDriver. Selenium currently supports multiple platforms – Windows and Linux, macOS, as well as most modern browsers IE, Firefox Chrome, Opera, Safari, Headless, Opera, Safari, and Chrome. You can script the test in many programming languages, including C#, Java Python, Ruby, and Python. This framework’s flexibility allows for complex and advanced test scripts that can be adapted to different levels of complexity. Selenium was the core of frameworks like Katalon Studio and Watir, Protractor and Robot Framework. It can also be used with BDD tools – Cucumber and Specflow.
Sikuli is an interesting cross-platform automation tool that can be used to create test scripts using “image based scripting”. Sikuli was developed by Rob Miller, Sean Tsung Hsiang Chang, Tom Yeh, and others in 2008. It allows you to automate everything visible on the screen, without needing any advanced knowledge of the internal API. Sikuli uses Jython as a programming language. In SikuliX, there is also the possibility to use Ruby. This tool uses imagesscreenshots to define parameters in its in-built functions. Sikuli is compatible with Windows, Linux, and macOS.
Katalon Studio. This framework is built on two powerful tools, Appium and Selenium. Katalon was built using the features of these frameworks and is now a powerful tool for testing web applications, mobile apps, and web services. It can be used by testers of different skill levels. Advanced testers can create their own libraries and use the recording feature. Katalon Studio and Katalon Analytics offer comprehensive views of reports, including charts, graphs, and metrics.
Watir stands to Web Application Testing in Ruby. As you can see, Watir is an open source family of Ruby libraries. Watir supports cross browser testing for most modern browsers, i.e. Firefox, Chrome and IE. Opera and Safari are all supported by Watir. Watir is a collection of smaller projects. Watir’s classic project is based on inbuild Ruby OLE. Watir’s webdriver is derived from Selenium 2.0. Watirspec is an executable specification for the Watir API.
Robot framework. This framework implements the keyword-driven acceptance testing approach and acceptance test-driven development. Robot framework can be used to test Web and Mobile applications. Additional test libraries can be added using Python or Java to extend its test capabilities. Selenium is also a popular combination for Robot framework.
We can see that the world of test automation offers many open-source solutions for improving your testing. While the list below shows the most popular tools, market trends continue to bring new cool tools to the forefront each year.