I've got about 6-7 J2EE apps running on my dev box at home, and then one prod site with 3 apps (2 of which are J2EE).
People can then get on my machine over the net and see the current status of an app in development before it gets loaded into prod.
The only issues are:
1. that i decided to prefix the EJBs with the application name so i didn't get a JNDI name collision when all the apps start loading.
e.g. call bean "myApp1/Billing" and "myApp2/Billing" instead of just "Billing".
2. obvious issues about restarting server brings down all apps, but seems to be ok just touching the application.xml which bounces only a single app at a time.