The runtime doesn't require additional licenses.

If you want to run a compiled application from a server (or any supported machine), then you prepare your application and deploy it. Runtime can be deployed in the same folder as your application, or to a "common" folder (in that case you need to deploy the xml that is created during compilation. This xml should point to the location where runtime is located). Take a look at the following link: Delivering your application to end users - - Application Techniques (appeon.com)

If you want to deploy using powerclient take a look at the information here: Working with a PowerClient project - - Users Guide (appeon.com)

Finally if your application is a cloud application using powerserver, this is the only case where you need to buy licenses, but for powerserver not for powerbuilder runtime.

Andreas.

Simply,

One Powerbuilder license, any number of developed applications could be deployed.  

HTH