Katalon Studio is a free automation testing tool that is powered by Selenium. It is designed to create and reuse automated test scripts for UI without coding, and allows for the testing of UI elements like pop-ups, iFrames, and wait time. Compared to Selenium, Katalon is easier to deploy, offers more integrations, and has features for analytics and reporting. It is extremely easy to set up and works immediately out of the box. However, it is not open source and its community is small, so support may be limited. It is best characterized as an emerging solution that works for small and medium size businesses.