What Is Apache Tomcat?

Apache Tomcat is a popular open source web server and Servlet container for Java code.

As the reference implementation of Java Servlet and Java Server Pages (JSP), Tomcat was started at Sun Microsystems, which later donated the code base to the Apache Software Foundation.

Since then, multiple volunteers from Sun contributed to the product which then led to a a top-level Apache project designation in 2005. Nowadays, Apache Tomcat is widely used by many companies as it implements many of the Java EE specifications, such as:

Java Servlet

JavaServer Pages,

Java Expression Language,

Java WebSockets.

Apache Tomcat 10.0.x is the current Tomcat release at the time of this writing, and is still undergoing active development. It is the first Tomcat release to support Java Servlet 5.0, JavaServer Pages 3.0, Java Expression Language 4.0, WebSocket 2.0, and Authentication 2.0 specifications.

Is Tomcat an Application Server, or a Web Server?

Tomcat is considered a web server instead of an application server because it functions as a web server and Servlet container. It doesn’t provide the full feature set from the Java EE, but that isn't necessarily a disadvantage. Many applications require just the features that Tomcat provides, so it doesn't make sense to go with the heavier tools. You can use Apache Tomcat for production applications that process thousands of requests if the features it provides is enough. In any case, Tomcat is a production-ready tool.

Is Tomcat Still Popular?

According to our 2022 Java Developer Productivity Report, Tomcat is used by 48% of Java teams. See the full data by downloading the report today.