Apache Tomcat

Apache Tomcat is an open source implementation of several Jakarta EE specifications, including Servlet, Pages, Expression Language, WebSocket, Annotations and Authentication. It provides a servlet container for running Java web applications and is released under the Apache License version 2. The project maintains separate release lines: Tomcat 11 implements Jakarta EE 11, Tomcat 10 implements Jakarta EE 10, and Tomcat 9 implements Java EE 8. Applications written for Tomcat 9 and earlier may require code changes to run on Tomcat 10 and later, since the primary API package changed from javax.* to jakarta.*.

The project offers related components including Tomcat Native, which provides OpenSSL-based TLS support, Tomcat Connectors for web server integration, the Apache Standard Taglib implementing JSTL 1.2, and a Maven plugin for manipulating WAR projects. The Tomcat Migration Tool for Jakarta EE assists with converting Java EE applications to Jakarta EE, either as a separate download or automatically when applications are placed in the webapps-javaee directory. Tomcat is available as free open source software under the Apache License version 2, with no paid editions or usage-based pricing.