Selenium is an open source tool that is used for automating the tests carried out on web browsers. The Selenium IDE provides a playback tool for authoring tests without the need to learn a test scripting language. It also provides a test domain-specific language (Selenese) to write tests in a number of popular programming languages, including C#, Groovy, Java, Perl, PHP, Python, Ruby and Scala. Selenium deploys on Windows, Linux, and macOS.