Invented by Craig McClanahan, Struts is an open-source project hosted by the Apache Software Foundation. At the time, it greatly simplified the JSP/Servlet programming paradigm and won over many developers who were using proprietary frameworks. It simplified the programming model, it was open source (and thus free as in beer), and it had a large community, which let the project grow and become popular among Java web developers.

As a successor to the original Struts 1.x, check out Struts 2.x and the Struts-provided Spring Plugin for the built-in Spring integration.