When deploying locally, the Mendix modeler uses a "build in" trail license. You don't have to update it or need a contract with Mendix. It just works for local deployment. Limitation is that the server will terminate after 2 hrs inactivity. also the number of concurrent users is limited to 10. Which works fine for local testing. The same concept is used when deploying to a sandbox . you don't have to worry about that license, Mendix just handles it.
Though when you want to run an app permanently a license is needed. link text
You will need a new license per application per server. But it is probably a good thing to contact Mendix to see if you can mix things up?
When deploying locally, the Mendix modeler uses a "build in" trail license. You don't have to update it or need a contract with Mendix. It just works for local deployment. Limitation is that the server will terminate after 2 hrs inactivity. also the number of concurrent users is limited to 10. Which works fine for local testing. The same concept is used when deploying to a sandbox . you don't have to worry about that license, Mendix just handles it.
Though when you want to run an app permanently a license is needed. link text