A ratpack web application in a shell script - just requires groovy (2.1+?) and JDK 1.7+ on the local machine.

hello_ratpack.sh

#!/usr/bin/env groovy

@GrabResolver("http://oss.jfrog.org/artifactory/libs-snapshot")
@Grab("org.ratpack-framework:ratpack-groovy:0.9.0-SNAPSHOT")
import static org.ratpackframework.groovy.RatpackScript.ratpack

ratpack {
  handlers {
    get {
      response.send "Hello ratpack!"
    }
  }
}