The portlet war file should be installed into
$PLATFORM_TOMCAT_HOME/webapps (in Tomcat) or
$PLATFORM_JBOSS_HOME/standalone/deployments (in JBoss).
Particularly for JBoss, you need to include a
to your portlet war, to declare platform.ear as a dependency:
<module name="deployment.platform.ear" export="true"/>
For more information, see Master Your Portlet Packaging in JBoss, Thomas Delhomenie.
Both Tomcat and JBoss support hot deployment.
To test your portlet in action, you need to add it to a page. This task can be done in two ways: