"JavaPoly.js is a library that polyfills native JVM support in the browser. It allows you to import your existing Java code, and invoke the code directly from Javascript."
The twelve-factor app is completely self-contained
using dependency declaration to add a webserver library to the app, such as Tornado for Python, Thin for Ruby, or Jetty for Java and other JVM-based languages.
the port-binding approach means that one app can become the backing service for another app
PHP processes run as child processes of Apache, started on demand as needed by request volume.
Java processes take the opposite approach, with the JVM providing one massive uberprocess that reserves a large block of system resources (CPU and memory) on startup, with concurrency managed internally via threads
Processes in the twelve-factor app take strong cues from the unix process model for running service daemons.