This blog post mentions support for using Kotlin as a scripting language with JSR-223 (the javax.script API).
I am very eager to try out this feature, but it doesn’t seem like Kotlin has a binding for kotlin, i.e. this test fails for me: kotlin/IdeaJsr223Test.kt at d335aea6821542d30840299b1a9c07468d081b62 · JetBrains/kotlin · GitHub
The reason it fails is because engine is null. Is there something I’m missing that I need to do to get it to work? 
This is specific test for JSR223 host in IntelliJ IDEA. You need to have an infrastructure to make it run. Generic JSR 223 examples are located here: kotlin/libraries/examples at master · JetBrains/kotlin · GitHub (kotlin-jsr223-*) and the “kotlin-jsr223-local-example” is easiest to follow and reuse.
Doubt the OP cares any more but for future searchers, the key steps to get it to work are:
You need these libraries in your class path (in additon to stdlib):
In addition, you need a META-INF/services/javax.script.ScriptEngineFactory file in the classpath jar to tell the JSR223 script engine to use the Kotlin script engine. Just adding the above libraries does not do it (probably a security concern). The easiest way to just add the file to your own jar like from this example: