Structure of an Atmosphere's Application

An Atmosphere's application structure must always contains the following files in order to maintains portability amongst WebServers

./META-INF
./META-INF/context.xml                             (1)
./WEB-INF
./WEB-INF/context.xml                              (2)
./WEB-INF/lib
./WEB-INF/lib/atmosphere-compat-jbossweb-1.0.0.jar (3)
./WEB-INF/lib/atmosphere-compat-tomcat-1.0.0.jar   (4)
./WEB-INF/lib/atmosphere-compat-tomcat7-1.0.0.jar  (5)
./WEB-INF/lib/atmosphere-runtime-1.0.0.jar         (6)
./WEB-INF/lib/slf4j-api-1.6.1.jar                  (7)

• (1) Required to execute on Tomcat
• (2) Required to execute on JBoss
• (3) Required to execute on all WebServer, optional in JBoss
• (4) Required to execute on all WebServer, optional in Tomcat 6
• (5) Required to execute on all WebServer, optional in Tomcat 7
• (6) Atmosphere's core classes, always required.
• (7) Logging library, always required.

You can remove some of the file if you don't need portability. For example Tomcat 6 only:

./META-INF
./WEB-INF/lib/atmosphere-compat-jbossweb-1.0.0.jar 
./WEB-INF/lib/atmosphere-compat-tomcat7-1.0.0.jar  
./WEB-INF/lib/atmosphere-runtime-1.0.0.jar         
./WEB-INF/lib/slf4j-api-1.6.1.jar                  

Tomcat 7 only:

./META-INF
./WEB-INF/lib/atmosphere-compat-jbossweb-1.0.0.jar 
./WEB-INF/lib/atmosphere-compat-tomcat-1.0.0.jar  
./WEB-INF/lib/atmosphere-runtime-1.0.0.jar         
./WEB-INF/lib/slf4j-api-1.6.1.jar                  

JBoss only:

./WEB-INF
./WEB-INF/lib/atmosphere-compat-tomcat7-1.0.0.jar  
./WEB-INF/lib/atmosphere-compat-tomcat7-1.0.0.jar  
./WEB-INF/lib/atmosphere-runtime-1.0.0.jar         
./WEB-INF/lib/slf4j-api-1.6.1.jar                  

Finally, if you are only deploying on WebServers that supports Servlet 3.0 by default, you can completely remove the context.xml file.