The Web Container is again a software that provides the runtime environment for JSP and Servlets to run.
For example - Apache Tomcat Server.
A Web Container (for example Apache Tomcat) has two different engines - called Catalina and Jasper. Catalina is a Servlet Engine, and Jasper is a JSP Engine.
The following is a list of applications which implement the Java Servlet specification.
Open source Web containers:
Apache Geronimo is a full Java EE 6 implementation by Apache Software Foundation.
Enhydra, from Lutris Technologies.
GlassFish from Oracle (an application server, but includes a web container).
Jetty, from the Eclipse Foundation. Also supports SPDY and WebSocket protocols.
Jaminid contains a higher abstraction than servlets.
Payara is another application server, derived from Glassfish.
Winstone supports specification v2.5 as of 0.9, has a focus on minimal configuration and the ability to strip the container down to only what you need.
Tiny Java Web Server (TJWS) 2.5 , small footprint, modular design.
Virgo from Eclipse Foundation provides modular, OSGi based web containers implemented using embedded Tomcat and Jetty. Virgo is available under the Eclipse Public License.
WildFly (formerly JBoss Application Server) is a full Java EE implementation by Red Hat, division JBoss.