JRuby is an implementation of the Ruby programming language atop the Java Virtual Machine, written largely in Java. It is free software released under a three-way EPL/GPL/LGPL license.
License: Open Source
Kotlin is a statically typed language that runs on the JVM, offering excellent performance and strong interoperability with Java, making it ideal for Android development. On the other hand, jRuby is a dynamic language that excels in web development, particularly with Ruby on Rails, and is more suited for scripting tasks but may lag in performance compared to compiled languages.