...Typically used for testing purposes or retrieving information from websites, HtmlUnit is not a generic unit testing framework but is intended to simulate a browser within another testing framework such as JUnit or TestNG. It is utilized as the underlying "browser" by various open source tools like WebDriver, Arquillian Drone, and Serenity BDD, and is employed by many projects for automated web testing, including Apache Shiro, Apache Struts, and Quarkus.