@joet3ch: REBOL is interesting language and quite different than the classic bunch. It’s a lot like a lisp without parenthesis. It’s absolutely homoiconic (code is data) that you can use in runtime for achieving interesting things. You can create your own dialects in it and it has various unique viewpoints (like 37 data types).
It also has some concrete problems, the biggest two that it’s currently used in practice version 2 is not open source and that development on it isn’t really active. The version 3, which is conceptually really awesome and partially open sourced has been dragging for ages. That’s why in last years few OS implementations of the concepts appeared, the most promising is Red (www.red-lang.org). The developments of Red is going great, but it still needs time to be practically useful.
@SteveMcLeod: I am not big on Java, JetBrains or Kotlin. But when I was making Android app I started looking for a solid more functional language (there are many langs. in JVM ecosystem now) that could be used instead of Java. I landed with Kotlin, which is really great (as c/algol based functional languages can get) and integrates Java / JVM perfectly! It can use any Java library directly, it can talk to Java code in a project and Java can talk to Kotlin. So I started rewriting Java classes in to Kotlin one by one, while the app still compiled and was functional. I considered Clojure and Scala also, but I had many reasons to prefer Kotlin.