Arquillian's forte is not only in its ease of use, but also in its flexibility. Good integration testing is not just about testing in any container, but rather testing in the container you are targeting. It's all too easy to kid ourselves by validating components in a specialized testing container, only to realize that the small variations causes the components fail when it comes time to deploy to the application for real. To make tests count, you want to execute them in the real container.

Arquillian supports a variety of target containers out of the box, which will be covered in this chapter. If the container you are using isn't supported, Arquillian makes it very easy to plug in your own implementation.