Selenium is a revolutionary web application testing tool. The open-source framework has automated the process of testing web applications. Functional tests can be performed without the need to use a scripting language to perform tests. It has a domain language called Selenese that is used for writing tests in a wide range of programming languages including Python, Java, Perl, C# and, Groovy. The open-source software under Apache License 2.0 runs on macOS, Linux and, Windows. The tool was developed in the year 2004 by Jason Huggins.