JAXenter: The motivation behind the proposal to deprecate Nashorn was that it is “challenging to maintain”.

Is Nashorn deprecated?

Nashorn is a deprecated JavaScript engine developed in the Java programming language by Oracle. It is based on the Da Vinci Machine (JSR 292) and has been included with Java 8 through JDK 14.

What is replacing Nashorn?

The Nashorn engine has been deprecated in JDK 11 as part of JEP 335 and and has been removed from JDK15 as part of JEP 372. GraalVM can step in as a replacement for JavaScript code previously executed on the Nashorn engine. GraalVM provides all the features for JavaScript previously provided by Nashorn.