If you prefer, TomEE can be setup by deploying a .war file into an existing Tomcat 7.x installation, as opposed to using the all-in-one bundle. This guide provides a set of step-by-step instructions to this approach. Please note that TomEE 1.7.x does not recommend Tomcat versions less than 7.0.54. Tomcat 8 is not currently supported in the released version, but you can check out the developer branch to see progress here.