What is Apache Tomcat? In web development, Apache Tomcat is an open-source web server and servlet container. It is designed to execute Java servlets and render JavaServer Pages(JSPs) to serve dynamic web content. Tomcat is widely used as a web application server for hosting Java-based web applications. It provides a Java Servlet API implementation and supports the Java Enterprise Edition (Java EE) specifications. Developers can write servlets and JSPs, which are Java-based components, and deploy them on Tomcat for execution.