Don Brown has created a pretty cool Maven plugin that allows you to run integration tests on multiple containers in one go. I learned about it on the Struts 2 Dev List:
I've started adding functional tests to Struts 2 by adding a few to the REST showcase application, running against Tomcat 5.x, Jetty 6.x, JBoss 4.2.x, and Resin 3.x. The magic happens through a new Maven 2 plugin I developed called maven-itblast-plugin, which enables multiple integration test runs against multiple containers in one go. For more info, see http://github.com/mrdon/maven-itblast-plugin/wikis/home.
You might notice that this plugin is hosted on GitHub. If you want to learn how to use GitHub with Maven, you might want to see Don's entry on Maven-enabled project hosting with GitHub. Thanks Don - good stuff.
Update: Don has posted more information about this plugin on his blog.