Test automation using Selenium has several advantages over manual testing such as allowing for frequent regression testing, rapid feedback to developers, and virtually unlimited test case execution. However, automation may not always be advantageous and manual testing is sometimes more appropriate, such as when user interfaces are changing frequently or when time constraints require testing to be completed quickly. Selenium IDE is a simple Firefox plugin that allows creating and exporting test cases without programming, but is limited and serious test automation requires using Selenium with a programming language.